Shine a light: A PtNiRu/TiO2 anode catalyst for direct ethanol fuel cells shows photocatalytic activity. The peak current density for ethanol oxidation under solar light illumination is 2–3 times greater than that in the absence of solar light. Ethanol is oxidized by light-generated holes, and the electrons are collected by the TiO2 support to generate the oxidation current.
Novel PtNiRu/TiO2 anode catalysts for direct ethanol fuel cells (DEFCs) were prepared from PtNiRu nanoparticles (1:1:1 atomic ratios) and a nanoporous TiO2 film by a sol-gel and electrodeposition method. The performances of the catalysts for ethanol oxidation were investigated by cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results indicate a remarkable enhancement of activity for ethanol oxidation under solar light illumination. Under solar light illumination, the generated oxidation peak current density is 24.6 mA cm−2, which is about 2.5 times higher than that observed without solar light (9.9 mA cm−2). The high catalytic activity of the PtNiRu/TiO2 complex catalyst for the electrooxidation of ethanol may be attributed to the modified metal/nanoporous TiO2 film, and the enhanced electrooxidation of ethanol under solar light may be due to the photogeneration of holes in the modified nanoporous TiO2 film.