Synthesis and Characterization of (Cu, S) Co‐doped SnO₂ for Electrocatalytic Reduction of CO₂ to Formate at Low Overpotential

Abstract

Abstract A novel copper (Cu) and sulfur (S) co‐doped SnO 2 material prepared by a facile hydrothermal method is demonstrated as an efficient electrocatalyst for the reduction of CO 2 to formate. The as‐prepared SC 10 holds rutile structure, whereas both Cu and S are doped well into the SnO 2 , in which S 2− and Cu 2+ replace O 2− and Sn 4+ , respectively. The overpotential observed in CO 2 ‐saturated 0.5 M NaHCO 3 solution is as low as 130 mV (vs. RHE) at −0.75 V (vs. Ag/AgCl) and the maximum current density also increases to 5.5 mA cm −2 at −1.2 V, which is 7‐times higher than pure SnO 2 . The catalyst is stable for more than 33 h and the Faradic efficiency of formate is 58.5 %. The as‐synthesized catalyst will open up a novel route for efficient reduction to formate and has a great potential for relieving the greenhouse effect.