Optically transparent hydrogen evolution catalysts made from networks of copper-platinum core-shell nanowires

This article reports the fabrication of copper-platinum core-shell nanowires by electroplating platinum onto copper nanowires, and the first demonstration of their use as a transparent, conducting electrocatalyst for the hydrogen evolution reaction (HER). Cu-Pt core-shell nanowire networks exhibit mass activities up to 8 times higher than carbon-supported Pt nanoparticles for the HER. Electroplating minimizes galvanic replacement, allowing the copper nanowires to retain their conductivity, and eliminating the need for a conductive substrate or overcoat. Cu-Pt core-shell nanowire networks can thus replace more expensive transparent electrodes made from indium tin oxide (ITO) in photoelectrolysis cells and dye sensitized solar cells. Unlike ITO, Cu-Pt core-shell nanowire films retain their conductivity after bending, retain their transmittance during electrochemical reduction, and have consistently high transmittance (>80%) across a wide optical window (300-1800 nm).