In Situ Growth and Activation of Ag/Ag2S Nanowire Clusters by H2S Plasma Treatment for Promoted Electrocatalytic CO2 Reduction

Abstract Nonmetallic activation of metal electrodes is effective and universal to improve the catalytic activity for the CO 2 reduction reaction. Here, selective electrocatalytic reduction of CO 2 is performed on a plasma‐activated Ag/Ag 2 S catalyst for the first time. By a facile H 2 S plasma treatment on Ag foil and subsequent electrochemical prereduction, Ag/Ag 2 S nanowire clusters are obtained in situ with different sizes. High Faradaic efficiency for CO generation on Ag/Ag 2 S is shifted to a significantly lower overpotential compared with untreated Ag foil with high current density. Density functional theory studies reveal that the promoted catalytic activity can be ascribed to the enhanced CO 2 activation and reduced reaction energy barrier of the limiting step.