In Situ Growth and Activation of Ag/Ag_2S Nanowire Clusters by H2S Plasma Treatment for Promoted Electrocatalytic CO_2 Reduction

摘要

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_2S catalyst for the first time. By a facile H2S plasma treatment on Ag foil and subsequent electrochemical prereduction, Ag/Ag_2S nanowire clusters are obtained in situ with different sizes. High Faradaic efficiency for CO generation on Ag/Ag_2S is shifted to a significantlylower 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.