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

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.