Selective CO2 Reduction on 2D Mesoporous Bi Nanosheets

Abstract The conversion of CO 2 to value‐added products using electrical or solar energy represents an attractive means for the capture and utilization of atmospheric CO 2 . Formate is a popular product from CO 2 reduction, but its reaction selectivity is usually unsatisfactory. Tin‐based materials have attracted the most attention for formate production at present. Unfortunately, most of them only exhibit moderate selectivity in a narrow and highly cathodic potential window. In this study, it is demonstrated that traditionally under‐explored bismuth has a much greater potential for formate production than tin or other materials. Mesoporous bismuth nanosheets are prepared here by the cathodic transformation of atomic‐thick bismuth oxycarbonate nanosheets. They enable the selective CO 2 reduction to formate with large current density, excellent Faradaic efficiency (≈100%) over a broad potential window and great operation stability. Moreover, Bi nanosheets are integrated with an oxygen evolution reaction electrocatalyst in full cells, and achieve efficient and robust solar conversion of CO 2 /H 2 O to formate/O 2 .