Surface Modification of Tin Dioxide via (Bi, S) Co‐Doping for Photoelectrocatalytic Reduction of CO 2 to Formate

Photoelectrocatalytic reduction of CO 2 into useful fuels is a promising approach in terms of climate challenge and energy crisis. In this paper, a novel SnO 2 ‐based catalyst doped with bismuth (Bi) and sulfur (S) was synthesized via a simple hydrothermal method for photoelectrocatalytic reduction of CO 2 . The as‐prepared catalyst demonstrates higher catalytic capability for CO 2 , in which the faradaic efficiency of formate reaches 55.6 % at an overpotential as low as ∼360 mV and the maximum current density is close to 9.33 mA.cm −2 at −1.4 vs Ag/AgCl with the doping ratio of 3 %, which is three times higher than pure SnO 2 . Meanwhile, the catalyst is more easily excited by visible light to reduce CO 2 due to the narrowing of band gap. The notable electrocatalytic performance for CO 2 reduction may be attributed to the defect caused by doping of Bi 3+ and S 2− into the lattice structure by replacing, respectively, Sn 4+ and O 2− . The catalyst may provide a novel strategy to promote the development of electrochemical reduction of CO 2 .