A Cu‐Based Nanoparticulate Film as Super‐Active and Robust Catalyst Surpasses Pt for Electrochemical H 2 Production from Neutral and Weak Acidic Aqueous Solutions

Electrocatalysts that are stable and highly active at low overpotential ( η ) under mild conditions as well as cost‐effective and scalable are eagerly desired for potential use in photo‐ and electro‐driven hydrogen evolution devices. Here the fabrication and characterization of a super‐active and robust Cu‐Cu x O‐Pt nanoparticulate electrocatalyst is reported, which displays a small Tafel slope (44 mV dec −1 ) and a large exchange current density (1.601 mA cm −2 ) in neutral buffer solution. The catalytic current density of this catalyst film reaches 500 mA cm −2 at η = −390 ± 12 mV and 20 mA cm −2 at η = −45 ± 3 mV, which are significantly higher than the values displayed by Pt foil and Pt/C electrodes in neutral buffer solution and even comparable with the activity of Pt electrode in 0.5 m H 2 SO 4 solution.