Preparation of Bi-Bi2S3 Catalyst to Promote Electron Transfer for CO2

Abstract

The electrocatalytic reduction of carbon dioxide to low carbon products by metal sulfide catalyst is a promising research topic in recent years. However, its performance is still insufficient for industrial application because of its low selectivity and conductivity. In this work, to enhance the performance of metal sulfide, we obtained Bi2S3, Bi-Bi2S3 and Bi catalysts by simple hydrothermal method through adjusting the solvent component ratio of DI water and N, N-Dimethylformamide. The results of electrochemical test and product analysis show that the formate Faradaic efficiency of Bi-Bi2S3 catalyst reached 85% at −1.0 V vs reversible hydrogen electrode and the maximum current density reached 17 mA cm−2, while the current density of Bi2S3 was 12.9 mA cm−2, and a stability for 12 h without obvious deactivation in the CO2-saturated 0.1 M KHCO3 was achieved. Through comparative experiments, it can be concluded that while Bi0 in Bi-Bi2S3 effectively improves the conductivity of sulfide materials, the better selectivity can be attributed to the introduction of sulfur and the synergistic effect of Bi2S3 and Bi0.