Electrochemical reduction of CO2 on defect-rich Bi derived from Bi2S3 with enhanced formate selectivity

Abstract

A sulphide-derived bismuth catalyst, synthesised from a one-pot hydrothermal reaction followed by electrochemical reduction, exhibits excellent performance for converting CO₂ into formate in an aqueous bicarbonate medium with high activity, selectivity and durability. The maximum faradaic efficiency of 84.0% for formate formation was achieved at an overpotential of 670 mV. A detailed study reveals that the lattice defects associated with the sulphide-derived Bi rather than residual sulphur are likely to engender a positive effect on the catalytic reduction of CO₂.