Electrochemical Reduction of CO2 to CO by N,S Dual-Doped Carbon Nanoweb Catalysts

Abstract

Converting CO2 into useful chemicals through an electrocatalytic process is an attractive solution to reduce CO2 in the atmosphere. However, the process suffers from high overpotential, low activity, or poor product selectivity. In this study, N,S dual-doped carbon nanoweb (NSCNW) materials were proposed as an efficient nonmetallic electrocatalyst for CO2 reduction. The NSCNW catalysts preferentially and rapidly converted CO2 into CO with a high Faradaic efficiency of 93.4 % and a partial current density of -5.93 mA cm(-2) at a low overpotential of 490 mV. A small Tafel slope value (93 mV dec(-1)) was obtained, demonstrating a high rate for CO2 reduction. Moreover, the catalysts also exhibited a quite stable current-density profile during 20 h with a high CO Faradaic efficiency above 90 % throughout the electrolysis reaction. The high catalytic performance of the catalysts for CO2 reduction could be attributed to synergistic effects associated with the structural advantages of 3 D carbon nanoweb structures and effective S doping of the carbon materials with the highest ratio of thiophene-like S to oxidized S species.