ChemPhysChem

Fire the photons: Photonic nanowire antennas efficiently funnel the emission of an embedded quantum light source into a directive optical beam. In this Minireview, the physics and realization of such devices are discussed. The authors consider both bottom-up and top-down fabrication routes and review potential applications to solid-state quantum optics and beyond.

Taking the heat: Thermally stable Brønsted acid sites are generated on Nb₂O₅/Al₂O₃ after calcination at high temperatures. Spectroscopic analysis shows that niobium oxide is supported as a monolayer domain and that the domains increase with increased loading up to 16 wt %. The Brønsted acid sites are generated at the boundaries of the niobium-oxide monolayer domains.

Grand designs: Grand canonical Monte Carlo simulations with a first-principles-based force field show that metal–organic frameworks (MOFs) with Li functional groups (i.e. CLi bonds) offer exceptional H₂ uptake at ambient temperature (see picture). For example, at 298 K and 100 bar, IRMOF-1-4Li shows a total H₂ uptake of 5.54 wt % and MOF-200-27Li exhibits a total H₂ uptake of 10.30 wt %, much higher than the corresponding values with pristine MOFs.

Repeatable nanobubble generation on a highly ordered pyrolytic graphite surface can be achieved by replacing water with saline solution or saline solution with water (see picture). Interestingly, nanobubbles are also observed by atomic force microscopy when saline liquids of different concentrations and valences are employed.

Simply sliding: The study of nanoscale tribology offers great potential in the fields of friction, wear, and lubrication. By considering a variety of hexagonal layered materials, including graphene, hexagonal boron nitride, and molybdenum disulfide, it is shown how a simple geometrical parameter, named the “registry index”, can capture the interlayer sliding energy landscape (see picture) as calculated by using advanced electronic structure methods as well as experimentally measured frictional behavior.