Efficient carbon dioxide electroreduction over rationally designed heterogeneous Ag2S-Au nanocomposites

Abstract

Electrochemical carbon dioxide reduction reaction (CO2RR) is regarded as an effective strategy to store abundant renewable energy and build a carbon neutral society. Gold (Au) and silver (Ag)-based catalysts for the effective electrochemical transformation of CO2 to CO emerge as promising candidates. Heterogeneous nanocomposites composed of noble metals and semiconductors exhibit great potential for electrocatalytic CO2 reduction through the electronic coupling effect at coherent interfaces. Herein, we successfully synthesize heterogeneous Ag2S-Au composite nanoparticles (NPs) as effective catalysts for CO production through CO2RR. At −0.8 V vs RHE, the heterogeneous Ag2S-Au nanocatalysts display a considerable CO Faradaic efficiency of 94.5%, and an appreciable CO partial current density of 9.17 mA cm−2. Moreover, they exhibit good stability for 30 h without obvious decrease. On the basis of density functional theory (DFT) calculations, it can be made clear that the heterogeneous Ag2S-Au interface is energetically more beneficial to the generation of COOH* intermediate for CO2RR. This study provides a new application for noble metal–semiconductor nanocomposites. © 2022 Elsevier Inc.