Not just sugar! Lewis-acidic Sn-MWW zeolites are obtained through postsynthesis functionalization of deboronated B-MWW with Sn. These materials are highly active, selective, and recyclable catalysts for the conversion of triose sugars to methyl lactate (in methanol) and lactic acid (in water). They also demonstrate good performance in the conversion of hexose sugars and sucrose to methyl lactate.

A self-biasing photoelectrochemical (PEC) cell that could work for spontaneous overall water splitting in a neutral solution was established based on the mismatched Fermi levels between the photoelectrodes. A Pt-catalyst-decorated crystalline silicon photovoltaic cell (Pt/PVC) was prepared and employed as an effective photocathode. This was coupled with a poly(ethylene glycol)-directed WO₃/W photoanode prepared by a hydrothermal process. Both of the photoelectrodes showed a response to visible light. The WO₃/W photoanode had a positively located valence band edge, the energy level of which was enough for water oxidation, and the Pt/PVC photocathode possessed a negatively located conduction band edge, which was capable of water reduction. More importantly, the Fermi level of the WO₃/W photoanode was more positive than that of the Pt/PVC photocathode because of the p–n junction of the PVC that decoupled the band bending and enlarged the photovoltage. Under visible-light irradiation, the WO₃/W photoanode provided a negative bias for the Pt/PVC photocathode, and the Pt/PVC photocathode provided a positive bias for the WO₃/W photoanode. An interior bias was generated that could relax the strict criteria of overall water splitting by cooperatively separating the hole–electron pairs at both photoelectrodes. In this system, the short-circuit current and the open-circuit voltage increased with increasing light intensity (AM 1.5 illumination) to reach 121 μA cm⁻² and 0.541 V, respectively, at a light intensity of 100 mW cm⁻². Such a combination provides a promising method for the fabrication of self-driven devices for solar-energy storage.

WO₃/W—wow! A self-biasing photoelectrochemical cell based on a Pt-catalyst-decorated crystalline silicon photovoltaic cell photocathode and WO₃/W photoanode that can be self-driven for overall water splitting under visible-light illumination is described.

Workin′ in a bromine: A palladium–polyoxometalate amphiphilic hybrid material serves as catalyst for oxidative brominations. The emulsion-based process avoids the use of toxic and corrosive bromination agents such as Br₂ or HBr, and uses molecular oxygen as oxidant. The only side product is water, which is also the reaction medium. The catalyst offers good recoverability and recyclability.

Organic dyes have become widely used in dye-sensitized solar cells (DSSCs) because of their good performance, flexible structural modifications, and low costs. To increase the photostability of organic dye-based DSSCs, we conducted a full study on the degradation mechanism of cyanoacrylic acid-based organic sensitizers in DSSCs. The results showed that with the synergy between water and UV light, the sensitizer could desorb from the TiO₂ surface and the cyanoacrylic acid unit of the sensitizer was transformed into the aldehyde group. It was also observed that the water content had a great effect on the degradation process. Our experiments conducted using ¹⁸O-labeled water demonstrated that the oxygen atom of the aldehyde group identified in the degraded dye came from the solvent water in the DSSCs. Therefore, controlling the water content during DSSC fabrication, good sealing of cells, and filtering the UV light are crucial to produce DSSCs that are more durable and robust.

Dye-ing to degrade: The degradation mechanism of cyanoacrylic acid-based organic sensitizers in dye-sensitized solar cells (DSSCs) has been studied. With the synergy of water and UV light, the sensitizer desorbs from the TiO₂ surface and the cyanoacrylic acid unit of sensitizer is converted into an aldehyde group. It is also observed that the oxygen atom of the aldehyde comes from the solvent water in DSSCs.

Perfluorosulfonic acid ionomers (PFSI) with different side-chain lengths have been investigated with respect to their morphology and electrochemical properties in vanadium flow batteries (VFB). The results indicated that the membrane with the shortest side chains (SSC-M2) displayed small ion clusters and a low degree of hydrophobic–hydrophilic separation, which is favourable to reduce the cross-over of vanadium ions in the VFB. SSC-M2 shows a similar proton conductivity to Nafion, which carries longer ionic side chains but with much lower ion permeability. As a result, the VFB assembled with SSC-M2 exhibited a superior coulombic efficiency and a voltage efficiency close to that of Nafion115. In situ mass transfer revealed that SSC-M2 had a remarkably low degree of vanadium and water transfer across the membrane, which resulted in lower capacity fading than in the case of Nafion115. These results indicate that a membrane with short side chains is an ideal option in the fabrication of high-performance VFBs with low capacity loss.

Membrane fame! A membrane with short side chains is proposed for vanadium flow batteries for the first time. This membrane (Aquivion-E87-12S) displays a much lower degree of hydrophobic–hydrophilic separation and exhibits superior coulombic efficiency than Nafion along with a remarkable capacity retention.

Down to the wire: Three-dimensional interconnected Si-based nanowires are produced through the combination of thermal decomposition of SiO and a metal-catalyzed nanowire growth process. This low-cost and scalable approach provides a promising candidate for high-capacity anodes in lithium-ion batteries.

Wax on, wax off: Bifunctional cobalt-based catalysts on zeolite supports are applied for the valorization of biosyngas through Fischer-Tropsch chemistry. By using these catalysts, waxes can be hydrocracked to shorter-chain hydrocarbons, increasing the selectivity towards the C₅–C₁₁ (gasoline) fraction. The zeolite topology and the amount and strength of acid sites are key parameters to maximize the performance of these bifunctional catalysts, steering Fischer-Tropsch product selectivity towards liquid hydrocarbons.

Cathodic reactions in biofilms employed in sediment microbial fuel cells is generally studied in the bulk phase. However, the cathodic biofilms affected by these reactions exist in microscale conditions in the biofilm and near the electrode surface that differ from the bulk phase. Understanding these microscale conditions and relating them to cathodic biofilm performance is critical for better-performing cathodes. The goal of this research was to quantify the variation in oxygen, hydrogen peroxide, and the pH value near polarized surfaces in river water to simulate cathodic biofilms. We used laboratory river-water biofilms and pure culture biofilms of Leptothrix discophora SP-6 as two types of cathodic biofilms. Microelectrodes were used to quantify oxygen concentration, hydrogen peroxide concentration, and the pH value near the cathodes. We observed the correlation between cathodic current generation, oxygen consumption, and hydrogen peroxide accumulation. We found that the 2 e⁻ pathway for oxygen reduction is the dominant pathway as opposed to the previously accepted 4 e⁻ pathway quantified from bulk-phase data. Biofouling of initially non-polarized cathodes by oxygen scavengers reduced cathode performance. Continuously polarized cathodes could sustain a higher cathodic current longer despite contamination. The surface pH reached a value of 8.8 when a current of only −30 μA was passed through a polarized cathode, demonstrating that the pH value could also contribute to preventing biofouling. Over time, oxygen-producing cathodic biofilms (Leptothrix discophora SP-6) colonized on polarized cathodes, which decreased the overpotential for oxygen reduction and resulted in a large cathodic current attributed to manganese reduction. However, the cathodic current was not sustainable.

A river runs through: Sediment microbial fuel cells are a new technology used to harness the natural redox gradients in sediments to produce usable energy. Microbial catalysis of oxygen reduction is often used to enhance the recovery of energy by sediment microbial fuel cells. It is demonstrated that microscale gradients of pH, oxygen, and hydrogen peroxide resulting from oxygen reduction negatively affects the colonization of micro-organisms on cathode surfaces that could be used in sediment microbial fuel cells.

Facing the pyramids by etching forward: Concave palladium polyhedra have been successfully prepared by selectively etching the {100} facets in situ by I⁻ ions. Due to the presence of a high density of atomic steps and surface relaxation, the concave palladium polyhedra exhibit an enhanced electrocatalytic activity towards ethanol oxidation.

Plasma increases activity: A one-step synthesis of Pt–C nanowire composites using a plasma co-deposition method is reported. Electrodes with a very low Pt loading can be obtained. Pt particles with sizes ranging from 1 to 2 nm are decorating the columnar carbon nanostructures because of strong interactions. The composite microstructure is responsible for a very high metal utilization rate as exemplified by reactions occurring in fuel cell electrodes.

We report the superior characteristics of a ZnO buffer layer covered with a phenothiazine-based, π-conjugated donor–acceptor (D–π–A)-type organic dye (called “d-ZnO”). The use of this system for the performance enhancement of inverted bulk heterojunction polymer solar cells (PSCs) with the configuration of indium tin oxide/d-ZnO/polymer:PC₇₁BM/MoO₃/Ag (PC₇₁BM=[6,6]-phenyl C₇₁ butyric acid methyl ester) is investigated. The layer of organic dyes anchored on the ZnO surface through carboxylate bonding reduces the shunt path on bare ZnO surface and provides better interfacial contacts and energy level alignments between the ZnO layer and the photoactive layer. This phenomenon consequently leads to highly enhanced photovoltaic parameters (fill factor, open-circuit voltage, and short-circuit current density) and power conversion efficiencies (PCEs). Inverted solar cells containing the d-ZnO layer not only revealed about 34 % (PCE: 4.37 %) and 18 % (PCE: 7.11 %) improvement in the PCEs of the representative poly-3(hexylthiophene) (P3HT) and low-band-gap poly{[4,8-bis-(2-ethyl-hexyl-thiophene-5-yl)-benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl]-alt-[2-(2’-ethylhexanoyl)-thieno[3,4-b]thiophen-4,6-diyl]} (PBDTTT-C-T) polymer systems, respectively, but also showed 2–4 times longer device lifetimes than their counterparts without the organic dye layer. These results demonstrate that this simple approach used in inverted PSCs with a metal oxide buffer layer could become a promising procedure to fabricate highly efficient and stable PSCs.

It’s a cover up! A new organic dye self-assembled on ZnO surface through carboxylate bonding has positive effects on the photovoltaic performance of inverted polymer solar cells (PSCs). This dye is based on a D–π–A system and can mediate forward charge transfers, reduce back charge recombination, passivate ZnO surface defects, and give good energy level alignments leading to largely enhanced efficiency and stability in inverted PSCs.

Feed the pore: A highly mesoporous melamine–formaldehyde resin is synthesized through a simple, one-step polycondensation reaction by using inexpensive and abundant common industrial chemicals. The material is demonstrated to have a high surface area and a well-defined pore structure. Its high density of CO₂ binding pockets with low CO₂ binding energy facilitates rapid and reversible CO₂ sorption.

Benign building blocks: Stereochemically pure diisocyanates were prepared on a multigram scale from succinic anhydride and isosorbide or isomannide. Characterization of polyurethanes that were produced from these diisocyanates revealed low polydispersity, high thermal stability, and stereochemistry-dependent morphology. If biobased succinic anhydride is used, then no stoichiometric petroleum-derived reagents are required in the synthesis of these materials.

Mild-mannered manipulation: A catalytic method for the conversion of carbohydrate biomass to γ-valerolactone in acidic aqueous media has been developed. The water-soluble iridium complexes were observed to be extremely catalytically active for providing γ-valerolactone in high yields with high TONs. The homogeneous catalysts can also be recycled and reused by applying a simple phase separation process.

Our best results jet: C₁₀ and C₁₁ branched alkanes, with low freezing points, are synthesized through the aldol condensation of furfural and methyl isobutyl ketone from lingocellulose, which is then followed by hydrodeoxygenation. These jet-fuel-range alkanes are obtained in high overall yields (≈90 %) under solvent-free conditions.

A solid polymer electrolyte prepared by using a solvent-free, scalable technique is reported. The membrane is formed by low-energy ball milling followed by hot-pressing of dry powdered polyethylene oxide polymer, LiCF₃SO₃ salt, and silane-treated Al₂O₃ (Al₂O₃-ST) ceramic filler. The effects of the ceramic fillers on the properties of the ionically conducting solid electrolyte membrane are characterized by using electrochemical impedance spectroscopy, XRD, differential scanning calorimeter, SEM, and galvanostatic cycling in lithium cells with a LiFePO₄ cathode. We demonstrate that the membrane containing Al₂O₃-ST ceramic filler performs well in terms of ionic conductivity, thermal properties, and lithium transference number. Furthermore, we show that the lithium cells, which use the new electrolyte together with the LiFePO₄ electrode, operate within 65 and 90 °C with high efficiency and long cycle life. Hence, the Al₂O₃-ST ceramic can be efficiently used as a ceramic filler to enhance the performance of solid polymer electrolytes in lithium batteries.

Polymer power: A polyethylene oxide-based electrolyte was prepared with the addition of silane-treated Al₂O₃ ceramic filler. The new ceramic additive leads to an enhancement of the ionic conductivity, thermal properties, and lithium transference number of the polymer electrolyte. The electrolyte can be efficiently used in lithium cells with a LiFePO₄ cathode, operating within 60–90 °C with a high capacity and a long cycle life.

Formic acid cracker: A mini plant that allows for continuous formic acid decomposition to hydrogen and carbon dioxide under ambient conditions is presented. By using an in situ-formed ruthenium catalyst, unprecedented turnover numbers over 1 000 000 are achieved. The active catalyst is formed in situ from commercially available [RuCl₂(benzene)]₂ and 1,2-bisdiphenylphosphinoethane.

Glycerol carbonate esters (GCEs), which are valuable biomass-derivative compounds, have been prepared through the direct esterification of glycerol carbonate and long organic acids with different chain lengths, in the absence of solvent, and with heterogeneous catalysts, including acidic-organic resins, zeolites, and hybrid organic–inorganic acids. The best results, in terms of activity and selectivity towards GCEs, were obtained using a Nafion–silica composite. A full reaction scheme has been established, and it has been demonstrated that an undesired competing reaction results in the generation of glycerol and esters derived from a secondary hydrolysis of the endocyclic ester group, which is attributed to water formed during the esterification reaction. The influence of temperature, substrate ratio, catalyst-to-substrate ratio, and the use of solvent has been studied and, under optimized reaction conditions and with the adequate catalyst, it was possible to achieve 95 % selectivity for the desired product at 98 % conversion. It was demonstrated that the reaction rate decreased as the number of carbon atoms in the linear alkyl chain of the carboxylic acid increased for both p-toluenesulfonic acid and Nafion–silica nanocomposite (Nafion SAC-13) catalysts. After fitting the experimental data to a mechanistically based kinetic model, the reaction kinetic parameters for Nafion SAC-13 catalysis were determined and compared for reactions involving different carboxylic acids. A kinetic study showed that the reduced reactivity of carboxylic acids with increasing chain lengths could be explained by inductive as well as steric effects.

Chain reaction: The esterification of glycerol carbonate with carboxylic acids to produce glycerol carbonate esters, which are valuable biomass-derivative compounds, has been investigated. A Nafion–silica nanocomposite is shown to be an excellent catalyst, and after fitting the experimental data to a kinetic model, the kinetic parameters were determined and compared for reactions involving different carboxylic acids.

RuC ees′ transfer: Transfer hydrogenation using alcohols as hydrogen donors and supported ruthenium catalysts results in the selective conversion of hydroxymethylfurfural to dimethylfuran (>80 % yield). During transfer hydrogenation, the hydrogen produced from alcohols is utilized in the hydrogenation of hydroxymethylfurfural.

Battery watch: UV/Vis spectrophotometry is demonstrated as a powerful analytical method for the in situ study of polysulfides. Through the interactions that occur between different chain-length polysulfide molecules and the UV/Vis radiation, quantitative and qualitative determination of the polysulfides formed during Li–S battery operation can be achieved.

Methane adsorption on positively charged aggregates of C₆₀ is investigated by both mass spectrometry and computer simulations. Calculated adsorption energies of 118–281 meV are in the optimal range for high-density storage of natural gas. Groove sites, dimple sites, and the first complete adsorption shells are identified experimentally and confirmed by molecular dynamics simulations, using a newly developed force field for methane–methane and fullerene–methane interaction. The effects of corrugation and curvature are discussed and compared with data for adsorption on graphite, graphene, and carbon nanotubes.

Snuggling of bucky and methane: What are the preferred adsorption sites of methane on small aggregates of C₆₀? How many methane molecules adsorb in groove sites? How many in dimple sites? We provide answers for aggregates containing up to four C₆₀ molecules. For example, this figure shows that seven CH₄ fit into the groove of the dimer, in excellent agreement with experiment. Calculated adsorption energies of 118–281 meV are in the optimal range for high-density storage of natural gas.

Carbon dioxide emitted from existing coal-fired power plants is a major environmental concern due to possible links to global climate change. In this study, we expand upon previous work focused on aminosilane-functionalized polymeric hollow-fiber sorbents by introducing a new class of polyethyleneimine (PEI)-functionalized polymeric hollow-fiber sorbents for post-combustion carbon dioxide capture. Different molecular weight PEIs (M_n≈600, 1800, 10 000, and 60 000) were studied as functional groups on polyamide imide (PAI, Torlon) hollow fibers. This imide ring-opening modification introduces two amide functional groups and was confirmed by FTIR attenuated total reflectance spectroscopy. The carbon dioxide equilibrium sorption capacities of PEI-functionalized Torlon materials were characterized by using both pressure decay and gravimetric sorption methods. For equivalent PEI concentrations, PAI functionalized with lower molecular weight PEI exhibited higher carbon dioxide capacities. The effect of water in the ring-opening reaction was also studied. Up to a critical value, water in the reaction mixture enhanced the degree of functionalization of PEI to Torlon and resulted in higher carbon dioxide uptake within the functionalized material. Above the critical value, roughly 15 % w/w water, the fiber morphology was lost and the fiber was soluble in the solvent. PEI-functionalized (M_n≈600) PAI under optimal reaction conditions was observed to have the highest CO₂ uptake: 4.9 g CO₂ per 100 g of polymer (1.1 mmol g⁻¹) at 0.1 bar and 35 °C with dry 10 % CO₂/90 % N₂ feed for thermogravimetric analysis. By using water-saturated feeds (10 % CO₂/90 % N₂ dry basis), CO₂ sorption was observed to increase to 6.0 g CO₂ per 100 g of sorbent (1.4 mmol g⁻¹). This material also demonstrated stability in cyclic adsorption–desorption operations, even under wet conditions at which some highly effective sorbents tend to lose performance. Thus, PEI-functionalized PAI fibers can be considered as promising material for post-combustion CO₂ capture.

Sucked in! Polyethyleneimine (PEI)-functionalized polymeric hollow-fiber sorbents for post-combustion carbon dioxide capture are described. Different molecular weight PEIs are studied as functional groups on polyamide imide (PAI) hollow fibers. For equivalent PEI concentrations, PAI functionalized with lower molecular weight PEI exhibit higher CO₂ capacities (see picture).

The development of new and improved processes for the synthesis of bio-based chemicals is one of the scientific challenges of our time. These new discoveries are not only important from an environmental point of view, but also represent an important economic opportunity, provided that the developed processes are selective and efficient. Bioethanol is currently produced from renewable resources in large amounts and, in addition to its use as biofuel, holds considerable promise as a building block for the chemical industry. Indeed, further improvements in production, both in terms of efficiency and feedstock selection, will guarantee availability at competitive prices. The conversion of bioethanol into commodity chemicals, in particular direct ‘drop-in’ replacements is, therefore, becoming increasingly attractive, provided that the appropriate (catalytic) technology is in place. The production of green and renewable 1,3-butadiene is a clear example of this approach. The Lebedev process for the one-step catalytic conversion of ethanol to butadiene has been known since the 1930s and has been applied on an industrial scale to produce synthetic rubber. Later, the availability of low-cost oil made it more convenient to obtain butadiene from petrochemical sources. The desire to produce bulk chemicals in a sustainable way and the availability of low-cost bioethanol in large volumes has, however, resulted in a renaissance of this old butadiene production process. This paper reviews the catalytic aspects associated with the synthesis of butadiene via the Lebedev process, as well as the production of other, mechanistically related bulk chemicals that can be obtained from (bio)ethanol.

Fuel for thought: The dedicated production of 1,3-butadiene from bioethanol is expected to be an effective solution to its current substantial price increase. The Lebedev process for ethanol-to-butadiene conversion is reviewed in detail. The Review also extends to other commodity chemicals that are produced from ethanol and are involved as intermediates or byproducts in the bio-based butadiene production process.

The functionalization of natural fibers is an important task that has recently received considerable attention. We investigated the formation of a hydrophobic layer from amphiphilic diblock copolymer micelles [polystyrene-block-poly(N-methyl-4-vinyl pyridinium iodide)] on natural fibers and on a model surface (mica). A series of micelles were prepared. The micelles were characterized by using cryoscopic TEM and light scattering, and their hydrophobization capability was studied through contact angle measurements, water adsorption, and Raman imaging. Mild heat treatment (130 °C) was used to increase the hydrophobization capability of the micelles. The results showed that the micelles could not hydrophobize a model surface, but could render the natural fibers water repellent both with and without heat treatment. This effect was systematically studied by varying the composition of the constituent blocks. The results showed that the micelle size (and the molecular weight of the constituent diblock copolymers) was the most important parameter, whereas the cationic (hydrophilic) part played only a minor role. We hypothesized that the hydrophobization effect could be attributed to a combination of the micelle size and the shrinkage of the natural fibers upon drying. The shrinking caused the roughness to increase on the fiber surface, which resulted in a rearrangement of the self- assembled layer in the wet state. Consequently, the fibers became hydrophobic through the roughness effects at multiple length scales. Mild heat treatment melted the micelle core and decreased the minimum size necessary for hydrophobization.

Rough and ready: A platform technology for the hydrophobization of natural fibers in water through amphiphilic block copolymer micelle adsorption onto fibers and subsequent heating. The natural roughening of the fibers upon drying facilitates hydrophobization, and heating reveals the hydrophobic core, which allows further hydrophobizing of the surface. Heat treatment tunes the effect of changes to the advancing water contact angles of 120° to 150°.

Emission of SO₂ in flue gas from the combustion of fossil fuels leads to severe environmental problems. Exploration of green and efficient methods to capture SO₂ is an interesting topic, especially at lower SO₂ partial pressures. In this work, ionic liquids (ILs) 1-(2-diethylaminoethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Et₂NEMim][Tf₂N]) and 1-(2-diethylaminoethyl)-3-methylimidazolium tetrazolate ([Et₂NEMim][Tetz]) were synthesized. The performances of the two ILs to capture SO₂ were studied under different conditions. It was demonstrated that the ILs were very efficient for SO₂ absorption. The [Et₂NEMim][Tetz] IL designed in this work could absorb 0.47 g g_IL⁻¹ at 0.0101 MPa SO₂ partial pressure, which is the highest capacity reported to date under the same conditions. The main reason for the large capacity was that both the cation and the anion could capture SO₂ chemically. In addition, the IL could easily be regenerated, and the very high absorption capacity and rapid absorption/desorption rates were not changed over five repeated cycles.

Say it ain′t SO₂! The ionic liquid [Et₂NEMim][Tetz] is synthesized and demonstrated to have an extremely high absorption capacity and rapid absorption/desorption rates for the capture of SO₂. [Et₂NEMim][Tetz] can be regenerated and reused, making it a very attractive ionic liquid for practical SO₂ capture applications.

CuInSe₂ (CISe) absorber layers for thin-film solar cells were fabricated through the selenization of amorphous Cu–In–S nanoparticles, which were prepared by using a low-temperature colloidal process within one minute without any external heating. Two strategies for obtaining highly dense CISe absorber films were used in this work; the first was the modification of nanoparticle surface through chelate complexation with ethanolamine, and the second strategy utilized the lattice expansion that occurred when S atoms in the precursor particles were replaced with Se during selenization. The synergy of these two strategies allowed formation of highly dense CISe thin films, and devices fabricated using the absorber layer demonstrated efficiencies of up to 7.94 % under AM 1.5G illumination without an anti-reflection coating.

CuInS a phase: An amorphous Cu–In–S nanoparticle-based route to form dense CuInSe₂ absorber layers for thin-film solar cells, in which the precursor nanoparticles are prepared within one minute of reaction without external heating, is demonstrated. A power conversion efficiency as high as 7.94 % is achieved by using this method.

Fertilizers based on phosphate–metal–humate complexes are a new family of compounds that represents a more sustainable and bioavailable phosphorus source. The characterization of this type of complex by using solid ³¹P NMR in several fertilizers, based on single superphosphate (SSP) and triple superphosphate (TSP) matrices, yielded surprising and unexpected trends in the intensity and fine structure of the ³¹P NMR peaks. Computational chemistry methods allowed the characterization of phosphate–calcium–humate complexes in both SSP and TSP matrices, but also predicted the formation of a stable sulfate–calcium–humate complex in the SSP fertilizers, which has not been described previously. The stability of this complex has been confirmed by using ultrafiltration techniques. Preference towards the humic substance for the sulfate–metal phase in SSP allowed the explanation of the opposing trends that were observed in the experimental ³¹P NMR spectra of SSP and TSP samples. Additionally, computational chemistry has provided an assignment of the ³¹P NMR signals to different phosphate ligands as well as valuable information about the relative strength of the phosphate–calcium interactions within the crystals.

Complex fertilizers: The combination of computational chemistry and traditional analysis allows the explanation of unexpected trends in the intensity and fine structure of the peaks obtained through ³¹P NMR spectroscopy for phosphate-based fertilizers. A sulfate–calcium-humate complex is predicted and confirmed, which has not previously been reported.

Nonaqueous lithium–oxygen batteries have a much superior theoretical gravimetric energy density compared to conventional lithium-ion batteries, and thus could render long-range electric vehicles a reality. A molecular-level understanding of the reversible formation of lithium peroxide in these batteries, the properties of major/minor discharge products, and the stability of the nonaqueous electrolytes is required to achieve successful lithium–oxygen batteries. We demonstrate that the major discharge product formed in the lithium–oxygen cell, lithium peroxide, exhibits a magnetic moment. These results are based on dc-magnetization measurements and a lithium–oxygen cell containing an ether-based electrolyte. The results are unexpected because bulk lithium peroxide has a significant band gap. Density functional calculations predict that superoxide-type surface oxygen groups with unpaired electrons exist on stoichiometric lithium peroxide crystalline surfaces and on nanoparticle surfaces; these computational results are consistent with the magnetic measurement of the discharged lithium peroxide product as well as EPR measurements on commercial lithium peroxide. The presence of superoxide-type surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as the reversible formation and decomposition of electrolyte molecules.

In a spin: The major discharge product formed in the lithium–oxygen cell, lithium peroxide, exhibits a magnetic moment. Density functional calculations predict that “superoxide-like” surface oxygen groups with unpaired electrons exist on nanoparticle surfaces, consistent with magnetic measurements of discharged lithium peroxide products. The “superoxide-like” surface oxygen groups with spin can play a role in the reversible formation and decomposition of lithium peroxide as well as electrolyte molecules.

Hausmannite Mn₃O₄ octahedral nanoparticles of 18.3±7.0 nm with (101) facets have been prepared by an oxygen-mediated growth. The electrochemical properties of the Mn₃O₄ particles as pseudocapacitive cathode materials were characterized both in half-cells and in button-cells. The Mn₃O₄ nanoparticles exhibited a high mass-specific capacitance of 261 F g⁻¹, which was calculated from cyclic voltammetry analyses, and a capacitive retention of 78 % after 10 000 galvanostatic charge–discharge cycles. The charge-transfer mechanisms of the Mn₃O₄ nanoparticles were further studied by using synchrotron-based in situ X-ray absorption near edge spectroscopy and XRD. Both measurements showed concurrently that throughout the potential window of 0–1.2 V (vs. Ag/AgCl), a stable spinel structure of Mn₃O₄ remained, and a reversible electrochemical conversion between tetrahedral [Mn^IIO₄] and octahedral [Mn^IIIO₆] units accounted for the redox activity. Density functional theory calculations further corroborated this mechanism by confirming the enhanced redox stability afforded by the abundant and exposed (101) facets of Mn₃O₄ octahedra.

Two-faced: Hausmannite Mn₃O₄ nanoparticles with (101) facets were prepared through oxygen-mediated growth. The Mn₃O₄ octahedral nanoparticles exhibited high mass-specific capacitance and cycle ability for supercapacitor reactions. The charge-storage mechanisms of the nanoparticles during electrochemical redox reactions were further studied by using in situ synchrotron-based methods.

Cellulose and cellobiose were selectively converted into sorbitol over water-tolerant phosphotungstic acid (PTA)/metal– organic-framework-hybrid-supported ruthenium catalysts, Ru-PTA/MIL-100(Cr), under aqueous hydrogenation conditions. The goal was to investigate the relationship between the acid/metal balance of bifunctional catalysts Ru-PTA/MIL-100(Cr) and their performance in the catalytic conversion of cellulose and cellobiose into sugar alcohols. The control of the amount and strength of acid sites in the supported PTA/MIL-100(Cr) was achieved through the effective control of encapsulated-PTA loading in MIL-100(Cr). This design and preparation method led to an appropriately balanced Ru-PTA/MIL-100(Cr) in terms of Ru dispersion and hydrogenation capacity on the one hand, and acid site density of PTA/MIL-100(Cr) (responsible for acid-catalyzed hydrolysis) on the other hand. The ratio of acid site density to the number of Ru surface atoms (n_A/n_Ru) of Ru-PTA/MIL-100(Cr) was used to monitor the balance between hydrogenation and hydrolysis functions; the optimum balance between the two catalytic functions, that is, 8.84<n_A/n_Ru<12.90, achieves maximum conversion of cellulose and cellobiose into hexitols. Under the applied reaction conditions, optimal results (63.2 % yield in hexitols with a selectivity for sorbitol of 57.9 % at complete conversion of cellulose, and 97.1 % yield in hexitols with a selectivity for sorbitol of 95.1 % at complete conversion of cellobiose) were obtained using a Ru-PTA/MIL-100(Cr) catalyst with loadings of 3.2 wt % for Ru and 16.7 wt % for PTA. This research thus opens new perspectives for the rational design of acid/metal bifunctional catalysts for biomass conversion.

Acid/Metal Balance: Bifunctional catalysts containing ruthenium and polyoxometalates as active species with a metal-organic framework as support and encapsulation matrix, respectively, are synthesized. Excellent yields in sorbitol are obtained in the conversion of cellobiose and ball-milled cellulose. The evaluation of the balance between the hydrogenation and hydrolysis functions of these bifucntional catalysts reveals that by carefully balancing the ratio of acid site density and the number of metal surface atoms a maximum conversion can be achieved.

A solid acid foam-structured catalyst based on a binderless zirconium phosphate (ZrPO) coating on aluminum foam was prepared. The catalyst layer was obtained by performing a multiple washcoating procedure of ZrPO slurry on the anodized aluminum foam. The effect of the pretreatment of ZrPO, the concentration of the slurry, and the amount of coating on the properties of the foam was studied. The catalytic properties of the prepared foams have been evaluated in the dehydration of glucose to 5-hydroxymethylfurfural (HMF) in a biphasic reactor. The catalytic behavior of ZrPO foam-based catalysts was studied in a rotating foam reactor and compared with that of bulk ZrPO. The effect of a silylation procedure on the selectivity of the process was shown over bulk and foam catalysts. This treatment resulted in a higher selectivity due to the deactivation of unselective Lewis acid sites. Addition of methylisobutylketone leads to extraction of HMF from the aqueous phase and stabilization of the selectivity to HMF over bulk ZrPO. A more intensive contact of the foam with the aqueous and organic phases leads to an increase in the selectivity and resistance to deactivation of the foam in comparison with a bulk catalyst.

Cat-Al-ytically coated: The preparation of a solid acid foam based on zirconium phosphate (ZrPO) coating on aluminum foam is described. The catalytic properties are evaluated in the dehydration of glucose to 5-hydroxymethylfurfural in a biphasic rotating foam reactor (see picture). The silylation procedure leads to a higher selectivity, and a more intensive contact of the foam with aqueous and organic phases leads to an increase of selectivity and stability.

Aqueous-phase reforming (APR) of biocarbohydrates is conducted in a catalytically stable washcoated microreactor where multiphase hydrogen removal enhances hydrogen efficiency. Single microchannel experiments are conducted following a simplified model based on the microreactor concept. A coating method to deposit a Pt-based catalyst on the microchannel walls is selected and optimized. APR reactivity tests are performed by using ethylene glycol as the model compound. Optimum results are achieved with a static washcoating technique; a highly uniform and well adhered 5 μm layer is deposited on the walls of a 320 μm internal diameter (ID) microchannel in one single step. During APR of ethylene glycol, the catalyst layer exhibits high stability over 10 days after limited initial deactivation. The microchannel presents higher conversion and selectivity to hydrogen than a fixed-bed reactor. The benefits of using a microreactor for APR can be further enhanced by utilizing increased Pt loadings, higher reaction temperatures, and larger carbohydrates (e.g., glucose). The use of microtechnology for aqueous-phase reforming will allow for a great reduction in the reformer size, thus rendering it promising for distributed hydrogen production.

Left out to dry: Aqueous-phase reforming (APR) of biocarbohydrates is conducted for the first time in a catalytically stable washcoated microchannel in which multiphase hydrogen removal enhances the hydrogen efficiency. The microchannel presents higher conversion of ethylene glycol and higher selectivity to hydrogen than a fixed-bed reactor. The use of microreactor technology for APR allows for a great reduction in the reformer size, which is promising for distributed hydrogen production.

The Cover Image shows the sequential dosing and purging of TiCl₄ and H₂O in atomic layer deposition (ALD) through step-like pressure changes in an effort to saturate the surface of fluorine doped tin oxide (FTO) glass with each reactant. These ultra-thin and uniform ALD TiO₂ films with thicknesses of only 5 nm form a blocking layer on the rough FTO surface to be used in dye-sensitized solar cells (see the report by Kim et al. on page 1014) as the yallow photogenerated electrons to move to the FTO side effectively, thus inhibiting the recombination with holes at the FTO/electrolyte interface.

Invited for this month′s cover is the group of Gregory Parsons at North Carolina State University. The image shows one cycle of TiO₂ atomic layer deposition (ALD), in which the sequential dosing and purging of TiCl₄ and H₂O forms ultrathin and conformal TiO₂ films on rough FTO glass. Pinhole-free ALD TiO₂ forms a blocking layer to impede electron–hole recombination at the FTO/electrolyte interface in dye-sensitized solar cells. The ALD process allows discrete tuning of the blocking-layer thickness to maximize performance improvement. Read the full text of the article at 10.1002/cssc.201300067

“It was difficult to obtain reliable and consistent results in each thickness.” This and more about the story behind the front cover research can be found on p. 930.

The conversion of CO₂ into fuels and chemicals is viewed as an attractive route for controlling the atmospheric concentration and recycling of this greenhouse gas, but its industrial application is limited by the low selectivity and activity of the current catalysts. Theoretical modeling, in particular density functional theory (DFT) simulations, provides a powerful and effective tool to discover chemical reaction mechanisms and design new catalysts for the chemical conversion of CO₂, overcoming the repetitious and time/labor consuming trial-and-error experimental processes. In this article we give a comprehensive survey of recent advances on mechanism determination by DFT calculations for the catalytic hydrogenation of CO₂ into CO, CH₄, CH₃OH, and HCOOH, and CO₂ methanation, as well as the photo- and electrochemical reduction of CO₂. DFT-guided design procedures of new catalytic systems are also reviewed, and challenges and perspectives in this field are outlined.

Calculating transformations: A comprehensive and critical review of the status of research in the field of the chemical conversion of CO₂ into carbon forms in a lower oxidation state is presented. Particular attention is devoted to the description of reaction mechanism of CO₂ transformation catalyzed by various types of systems (heterogeneous, homogeneous, and electro- and photocatalysts) and to the possible essential role that theoretical and computational approaches can play in this field.

In view of their possible use as anode materials in acid direct ethanol fuel cells, the electrocatalytic activity of Pt–Ru and Pt–Ru–M catalysts for ethanol oxidation has been investigated. This minireview examines the effects of the structural characteristics of Pt–Ru, such as the degree of alloying and Ru oxidation state, on the electrocatalytic activity for ethanol oxidation.

Packing a punch: The effect of structural parameters on the ethanol oxidation reaction (EOR) activity of Pt–Ru catalysts is discussed. The EOR activity versus Ru content plots of Pt–Ru catalysts prepared by using different methods go through a maximum, depending on the synthesis method (see image). Alloyed Ru supports ethanol dehydrogenation. Non-alloyed Ru, in the RuO_xH_y form, supports the oxidation of intermediates species in ethanol oxidation.

Sloshing hydrogen: Liquid organic hydrogen carriers are high-boiling organic molecules, which can be reversibly hydrogenated and dehydrogenated in catalytic processes and are, therefore, a promising chemical hydrogen storage material. One of the promising candidates is the pair N-ethylcarbazole/perhydro-N-ethylcarbazole (NEC/H₁₂-NEC). The dehydrogenation and possible side reactions on a Pt(111) surface are evaluated in unprecedented detail.

Safe only in a microreactor! The synthesis of adipic acid from cyclohexene by tungstic acid-catalyzed oxidation using hydrogen peroxide following the classical Noyori protocol can be accomplished in good yields with residence times as short as 20 min at 140 °C using a safe and scalable microreactor environment. Under these intensified conditions the use of a phase-transfer catalyst is not required.

Changing the sheets: Hollow TiO₂ porous nanosheets (HTPNs) are prepared on ITO glass through an improved TiO₂ polycrystalline shell-assisted cation exchange by using ZnO porous nanosheets (grown by using indirect electrodeposition) as a template. Quantum dot-sensitized solar cells based on HTPNs exhibit a high performance, and other photoelectrochemical devices are expected to be prepared based on HTPNs.

Some like it hot: Lactic acid is an important commodity chemical that is mainly used in the food industry or for the manufacture of biodegradable plastics. A highly efficient strategy for the conversion of carbohydrates from biomass to lactic acid through alkaline hydrolysis in superheated water is presented.

Carb your enthousiasm: Carbazole-based sensitizers with high extinction coefficients are synthesized for application in dye-sensitized solar cells (DSCs). The dyes perform efficiently with both iodine and cobalt electrolytes, showing power conversion efficiencies of up to 5.8 % on TiO₂ films of 15 μm thickness, and retaining 90 % of their efficiency in devices with thinner films.

Sweets for my sweet: The production and isolation of 5-hydroxymethylfurfural (HMF) in high yield and purity is demonstrated by using a combination of glucose–fructose isomerization with sweetzyme in wet tetraethylammonium bromide (TEAB) and clean fructose dehydration to HMF catalyzed by using HNO₃ under moderate conditions, which allow the reuse of any unreacted glucose and TEAB.

Committed carbenes: The convenient application of bidentate carbene ligands is described for the hydrogenation of carboxylic acid esters. The ligand precursors are easily synthesized through the dimerization of N-substituted imidazoles with diiodomethane. The catalyst is generated in situ and exhibits good activity and functional group tolerance for the hydrogenation of aromatic and aliphatic carboxylic acid esters.

A series of Pt catalysts supported on Al₂O₃ that was doped with different amounts of CeO₂ was developed, characterized, and tested in the aqueous-phase reforming (APR) of glycerol to H₂. Catalyst 3Pt/3CeAl, which bore 3 wt % Pt on a support that contained 3 wt % CeO₂, showed the highest carbon conversion to gas (85 %) and the highest H₂ yield (80 %) for a feedstock of 1 wt % glycerol in water at 240 °C and 40 bar. A CeO₂/Al₂O₃ support with only 1 wt % Pt also showed high H₂ selectivity and carbon conversion to gas, as well as a much lower CH₄ yield than the benchmark 3Pt/Al catalyst, clearly demonstrating that doping the support with 3 wt % CeO₂ improved the APR of glycerol. H₂ chemisorption results showed that the highest metal dispersion (58 %) and active surface area (4.3 m² g⁻¹) were achieved for the support that contained 3 wt % CeO₂, and this effect appeared to be primarily responsible for the high H₂ yield and carbon conversion to gas. No CO was observed in the product gas; therefore, this gas could potentially be used directly in proton exchange membrane fuel cells. Thus, including CeO₂ in the Al₂O₃ catalyst support enhanced both the activity and selectivity towards H₂ of a Pt catalyst for the APR of glycerol.

Pt darn good: Pt catalysts supported on CeO₂-doped Al₂O₃ exhibit higher activity and selectivity towards H₂ production in the aqueous-phase reforming of glycerol. Optimization of the CeO₂/Al₂O₃ ratio, higher metal dispersion, and increased active surface area are primarily responsible for the higher glycerol conversion rate and H₂ yield.

Dye-sensitized solar cells (DSSCs) often use a thin insulating or semiconducting layer (typically TiO₂) between the transparent conductive oxide and the mesoporous TiO₂ to block electron/hole recombination at the conducting oxide/electrolyte interface. The blocking layer (BL) is essential to maintain efficient charge generation under low light conditions, at which DSSCs perform well compared to common semiconductor-based photovoltaic devices. In this work, we show that atomic layer deposition (ALD) can produce ultrathin (<10 nm) BLs that significantly impede charge recombination in functional DSSCs, leading to improved photocurrents, open-circuit photovoltages, and fill factors; this results in an increase in the overall efficiency from ≈7 % to ≈8.4 % under AM 1.5 G illumination. The 5–10 nm ALD BLs are the thinnest optimized DSSC BLs reported to date. The BL retards the open-circuit voltage decay and extends the electron lifetime from ≈0.2 s to more than 10 s at 0.3 V, confirming that the ALD films significantly impede photogenerated charge recombination. By preparing BLs through other deposition techniques, we directly demonstrate that ALD results in better performance, even with thinner films, which is ascribed to the lower pinhole density of ALD materials.

Plugging the hole: Atomic layer deposition (ALD) produces ultrathin (<10 nm) blocking layers (BLs) that significantly impede charge recombination in functional dye-sensitized solar cells (DSSCs). This leads to improved photocurrents, open-circuit photovoltages, and fill factors, which increase the overall efficiency from ≈7 % to ≈8.4 % under AM 1.5 G illumination. The 5–10 nm ALD BLs are the thinnest optimized DSSC BLs reported to date.

The high activity and selectivity of zeolites in the cyclisation of unsaturated alcohols is reported for the first time; the details of a reaction mechanism based on quantum chemical calculations are also provided. The high efficiency of zeolites MFI, BEA and FAU in the cyclisation of unsaturated alcohols (cis-decen-1-ol, 6-methylhept-5-en-2-ol and 2-allylphenol) to afford oxygen-containing heterocyclic rings is demonstrated. The best catalytic performance is found for zeolites with the optimum concentration of Brønsted acid sites (ca. 0.2 mmol g⁻¹) and the minimum number of Lewis acid sites. It is proposed that the efficiency of the catalysts is reduced by the existence of the so-called dual site, at which a molecule of unsaturated alcohol can simultaneously interact with two acid sites (an OH group with one and the double bond with the other Brønsted site), which increases the interaction strength. The formation of such adsorption complexes leads to a decrease in the catalyst activity because of (i) an increase in the reaction barrier, (ii) an unfavourable conformation and (iii) diffusion limitations. A new procedure for the preparation of tetrahydrofurans and pyrans over zeolite catalysts provides important oxygen-containing heterocycles with numerous applications.

The zeolite fantastic: The high efficiency of zeolites MFI, BEA and FAU in the cyclisation of unsaturated alcohols to afford oxygen-containing heterocyclic rings is demonstrated. It is proposed that the efficiency of the catalysts depends on the existence of the so-called dual site, at which a molecule of an unsaturated alcohol can simultaneously interact with two acid sites.

The functionalization of micro- and nano-sized metal-oxide powders offers many advantages because of their large surface areas and, therefore, the large number of functional molecules that can be grafted onto the grain surfaces. Porphyrin molecules on large band-gap semiconducting metal oxides represent key materials for many different optical and electronic applications. Herein, we have proposed a general two-step procedure for the functionalization of metal-oxide crystals with dye-sensitizers. In particular, we functionalized SnO₂ nanoparticles with a monolayer of the bifunctional trichloro[4-(chloromethyl)phenyl]silane. Then, a monolayer of 5,10,15,20-tetrakis(4-hydroxyphenyl)-21H,23H-porphyne was covalently bound to the silanized SnO₂ grains. IR, UV/Vis, and luminescence measurements were used for optical characterization. The measured footprint of the grafted porphyrin molecules indicated total surface coverage of the grains. The surface electronic characterization was performed by using X-ray photoelectron spectroscopy. Emission measurements revealed two strong bands at 664.1 and 721.0 nm that were attributed to the porphyrin monolayer assembled on the surface of the SnO₂ crystals.

All wrapped up: SnO₂ crystals are functionalized with a porphyrin monolayer and the resulting functionalized material is fully characterized. The obtained system shows luminescent properties and has the potential to find application in optical and electronic devices. The two-step procedure for the functionalization of metal-oxide crystals with dye-sensitizers could be applied to a range of metal-oxide semiconductors.

We report a new class of quaternary polymer electrolyte membranes that comprise poly(ethylene oxide) (PEO), lithium trifluoromethanesulfonylimide (LiTFSI), N-alkyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr_A,4TFSI) as an ionic liquid, and a SiO₂ filler. The results of differential scanning calorimetry indicate that the addition of SiO₂ and different ionic liquids induces a decrease in the PEO melting enthalpy, which thereby increases the ionic conductivity and the Li transference number. The electrochemical stability is proved by using impedance spectroscopy and cyclic voltammetry. Galvanostatic cycling of Li/LiFePO₄ cells, which comprise the quaternary polymer electrolytes, revealed their superior performance compared to conventional PEO-Li salt electrolytes. In the course of this investigation, a synergistic effect of the combined ionic liquid-ceramic filler modification could be proved at temperatures close to 50 °C.

Electrolyte right! A new and attractive electrolyte based on polyethylene oxide and N-butyl-N-ethyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid as plasticizer shows high conductivity at medium to low temperatures. This allows its employment in a solid polymer lithium battery using LiFePO₄ as the cathode and its efficient operation at temperatures of about 50 °C.

Intensive research on oxygen reduction reaction (ORR) catalysts has been undertaken to find a Pt substitute or reduce the amount of Pt. Ag nanoparticles are potential Pt substitutes; however, the weak oxygen adsorption energy of Ag prompted investigation of other catalysts. Herein, we prepared AgCu bimetallic nanoparticle (NP) systems to improve the catalytic performance and compared the catalytic performance of Ag, Cu, AgCu (core–shell), and AgCu (alloy) NP systems as new catalyst by investigating the adsorption energy of oxygen and the activation energy of oxygen dissociation, which is known to be the rate-determining step of ORR. By analyzing HOMO-level isosurfaces of metal NPs and oxygen, we found that the adsorption sites and the oxygen adsorption energies varied with different configurations of NPs. We then plotted the oxygen adsorption energies against the energy barrier of oxygen dissociation to determine the catalytic performance. AgCu (alloy) and Cu NPs exhibited strong adsorption energies and low activation-energy barriers. However, the overly strong oxygen adsorption energy of Cu NPs hindered the ORR.

AgCu (alloy) nanoparticle: The adsorption energy of oxygen and the activation energy of oxygen dissociation are important factors that determine the performance of oxygen reduction reaction catalysts. We propose the utilization of a AgCu-alloy nanoparticle system as a potential highly efficient catalyst in this setting because it possesses good catalytic properties and prevents Cu oxidation.

Azole anions are key components in CO₂ capture materials that include ionic liquids and porous solids. Herein, we use density functional theory (DFT) and a Langmuir-type adsorption model to study azole anion–CO₂ interactions. Linear CO₂ has to be bent by approximately 45° to form an NC bond within the azole ring. The energy cost of bending renders CO₂ absorption much more difficult compared to SO₂ absorption. For different azole anions, the number of nitrogen atoms in the ring and the natural bond orbital energy of the reacting nitrogen lone pair, both linearly correlate with the calculated reaction enthalpy and are useful handles for new sorbent designs. Unlike for SO₂, the azole parent architecture (unsubstituted) does not allow successive CO₂ absorption under mild conditions (<0.12 MPa and at room temperature). Experimental CO₂ and SO₂ absorption isotherms are reproduced by using the Langmuir model parameterized with the calibrated DFT reaction enthalpies. This study provides insight for designing azole-based CO₂-capture materials.

Catch me if you can: Azole anions represent a key component in CO₂ absorption materials. A variety of different azole anions have been investigated for their reactivity with CO₂ by using DFT calculations and a Langmuir adsorption model. Unlike SO₂, multi-site CO₂ absorption does not occur for azole anions under normal conditions. This study provides insight into designing azole-based CO₂-capture materials.

Highly porous activated carbon with a large surface area and pore volume was synthesized by KOH activation using commercially available activated carbon as a precursor. By modification with polydimethylsiloxane (PDMS), highly porous activated carbon showed superhydrophobicity with a water contact angle of 163.6°. The changes in wettability of PDMS- treated highly porous activated carbon were attributed to the deposition of a low-surface-energy silicon coating onto activated carbon (confirmed by X-ray photoelectron spectroscopy), which had microporous characteristics (confirmed by XRD, SEM, and TEM analyses). Using an easy dip-coating method, superhydrophobic activated carbon-coated sponges were also fabricated; those exhibited excellent absorption selectivity for the removal of a wide range of organics and oils from water, and also recyclability, thus showing great potential as efficient absorbents for the large-scale removal of organic contaminants or oil spills from water.

Supersponge, save the world! Superhydrophobic activated carbon-coated sponges show good selectivity, recyclability, and absorbencies ranging from 2695 to 8586 wt % for a wide range of organic solvents and oils. These materials may have useful applications especially in the fields of oil-spill cleanup and water treatment.

Catalytic dehydration of D-fructose to 5-hydroxymethylfurfural (HMF) was investigated over a series of Nafion-modified mesocellular silica foam (MCF) materials. By using an impregnation method, Nafion resin was highly dispersed in the ultra-large pores of the MCFs. Highly efficient and selective dehydration of D-fructose to HMF was achieved in dimethyl sulfoxide solvent; an 89.3 % HMF yield with 95.0 % selectivity was obtained in the presence of the Nafion(15)/MCF catalyst. The effects of reaction temperature, reaction time, and solvent on the dehydration of D-fructose were systematically investigated. The catalyst could be regenerated through an ion-exchange method and a high yield was retained after being used five times. As a heterogeneous catalytic process, a possible reaction mechanism for the dehydration of D-fructose over Nafion-modified MCF catalysts was proposed.

Valuable sugars: Nafion-resin-functionalized mesocellular silica foam (MCF) is a strong solid acid that can be prepared through an impregnation method. By using this method, Nafion is well-dispersed in the ultra-large cells of MCFs. This material can easily be reused and exhibits high efficiency and selectivity for the acid-catalyzed dehydration of D-fructose to 5-hydroxymethylfurfural under mild conditions.

A high current density obtained in a limited, nanometer-thick region is important for high efficiency polymer solar cells (PSCs). The conversion of incident photons to charge carriers only occurs in confined active layers; therefore, charge-carrier extraction from the active layer within the device by using solar light has an important impact on the current density and the related to power conversion efficiency. In this study, we observed a surprising result, that is, extracting the charge carrier generated in the active layer of a PSC device, with a thickness-controlled PEDOT:PSS bilayer that acted as a hole extraction layer (HEL), yielded a dramatically improved power conversion efficiency in two different model systems (P3HT:PC₆₀BM and PCDTBT:PC₇₀BM). To understand this phenomenon, we conducted optical strength simulation, photocurrent–voltage measurements, incident photon to charge carrier efficiency measurements, ultraviolet photoelectron spectroscopy, and AFM studies. The results revealed that approximately 60 nm was the optimum PEDOT:PSS bilayer HEL thickness in PSCs for producing the maximum power conversion efficiency.

Two layers are better than one: The systematic increase in power conversion efficiency of polymer solar cells (PSCs) is demonstrated by considering the charge carrier transfer and electric field strength of a device. The unexpected and greatly enhanced power conversion efficiency of PSCs is reported, which can be accomplished by using a PEDOT:PSS hole extraction bilayer. Two different model systems are studied: P3HT:PC₆₀BM and PCDTBT:PC₇₀BM.

A highly stable high-temperature CO₂ sorbent consisting of scaffold-like Ca-rich oxides (CaAlO) with rapid absorption kinetics and a high capacity is described. The Ca-rich oxides were prepared by annealing CaAlNO₃ layered double hydroxide (LDH) precursors through a sol–gel process with Al(OⁱP)₃ and Ca(NO₃)₂ with Ca²⁺/Al³⁺ ratios of 1:1, 2:1, 4:1, and 7:1. XRD indicated that only LDH powders were formed for Ca²⁺/Al³⁺ ratios of 2:1. However, both LDH and Ca(OH)₂ phases were produced at higher ratios. Both TEM and SEM observations indicated that the CaAlNO₃ LDHs displayed a scaffold-like porous structure morphology rather than platelet-like particles. Upon annealing at 600 °C, a highly stable porous network structure of the CaO-based CaAlO mixed oxide (CAMO), composed of CaO and Ca₁₂Al₁₄O₃₃, was still present. The CAMO exhibited high specific surface areas (up to 191 m² g⁻¹) and a pore size distribution of 3–6 nm, which allowed rapid diffusion of CO₂ into the interior of the material, inducing fast carbonation/calcination and enhancing the sintering-resistant nature over multiple carbonation/calcination cycles for CO₂ absorption at 700 °C. Thermogravimetric analysis results indicated that a CO₂ capture capacity of approximately 49 wt % could be obtained with rapid absorption from the porous 7:1 CAMO sorbents by carbonation at 700 °C for 5 min. Also, 94–98 % of the initial CO₂ capture capability was retained after 50 cycles of multiple carbonation/calcination tests. Therefore, the CAMO framework is a good isolator for preventing the aggregation of CaO particles, and it is suitable for long-term cyclic operation in high-temperature environments.

Caught in a web: A CaAl layered double hydroxide-based scaffold-like network is synthesized in the presence of hexadecyl trimethyl ammonium bromide (CTAB) by using a sol–gel process with Al(OⁱP)₃ and Ca(NO₃)₂ as precursors. The calcined CaAlNO₃ layered double hydroxides display rapid CO₂ absorption kinetics in addition to a long-term cyclic operation in a high-temperature environment.

Graphene is considered as a rising-star material because of its unique properties and it is a promising material for applications in many fields. In recent years, experiments on graphene fabricated by using versatile methods have shed light on the crucial problem of aggregation and restacking, which is induced by strong π–π stacking and van der Waals forces, but preparation methods for real-world applications are still a great challenge. Here we report a facile, rapid, and environmentally friendly process, the burn–quench method, that allows large-scale and controlled synthesis of ordered mesoporous nanographene with 1–5 layers, which has a high surface area and electric conductivity. Electrodes composed of nanographene with a mesoporous architecture used both in electrochemical capacitors and lithium-ion batteries have a high specific capacitance, rate capability, energy density, and cyclic stability. Our results represent an important step toward large-scale graphene synthesis based on this new burn–quench method for applications in high-performance electrochemical energy storage devices.

Nanographene electrodes are go: The large-scale production of nanographene with a controlled mesoporous architecture is achieved by a new burn–quench method, which involves the ignition of Mg ribbons in CO₂ followed by in situ quenching. Nanographene with a mesoporous architecture has a high surface area and high conductivity.

The oxygen reduction reaction (ORR) is undoubtedly the most important fuel-cell cathodic reaction. In this work, a detailed electrochemical analysis of the ORR on Pt (111) in nonadsorbing electrolytes was performed, which included the high-potential region E_up=1.15 V while ensuring the electrode surface structure stability. Our results suggest that the reduction of a soluble intermediate species formed during the ORR is the rate-determining step in the whole reaction mechanism. This species does not undergo any other electrochemical reaction at E>0.9 V and may accumulate close to the electrode surface. Together with dissolved O₂, this intermediate may modify the oxide-growth dynamics on Pt (111). Hence, both species interact with the electrode surface through complex catalytic networks. Under certain experimental conditions, oxygenated species from the oxidation of Pt (111) may enhance the overall ORR current. These results propose an alternative to explain the current state of the art for this fundamental process.

A radical idea! The oxygen reduction reaction on Pt (111) in the high potential region is not inhibited by the initial oxidized surface states. Instead, the reduction of a soluble intermediate species apparently is the rate determining step.