Boosting CO2 Electroreduction via Construction of a Stable ZnS/ZnO Interface.

Abstract

Carbon dioxide (CO2) electroreduction can offer a way of relieving environmental and energy issues. Gold and silver catalysts show considerable electrochemical performance for CO production; however, the electrochemical CO2 conversion to CO is still restricted by the Faradaic efficiency, current density, and stability over the catalysts. Non-noble metal (zinc) is considered as a promising catalyst for CO2 electroreduction because of its low cost. However, because of the electron-rich property of zinc, it has a weak adsorption capacity of intermediates, resulting in a poor CO2 electroreduction performance. In this work, ZnS nanoparticles are embedded onto the ZnO surface to construct a stable ZnS/ZnO interface structure. The ZnS/ZnO interface reaches a maximum current density of 327.2 ± 10.6 mA cm-2 with a CO Faradaic efficiency of 91.9 ± 0.6% at -0.73 V vs a reversible hydrogen electrode (RHE) and remains stable for 40 h at a current density of 115.7 ± 7.0 mA cm-2 with a CO Faradaic efficiency of 93.8 ± 3.7% at -0.56 V vs RHE.