Bismuth-Nanosheet-Based Catalysts with a Reconstituted Bi0 Atom for Promoting the Electrocatalytic Reduction of CO2 to Formate

The electrocatalytic reduction of CO2 shows significant potential for the conversion of CO2 to valuable chemicals and fuels. Herein, we develop a method for the preparation of two-dimensional Bi-based catalysts by the reconstitution of a Bi-0 atom (re-Bi NSs). In situ Raman spectral analysis reveals that the reconstituted fresh Bi-0 is the electrocatalytic active center, while Bi-III is not. The as-prepared electrocatalyst exhibits excellent electrocatalytic activity for the generation of formate with a high faradaic efficiency (FEformate) of over 90% at an applied potential from -0.8 to -1.2 V versus reversible hydrogen electrode (RHE), with the corresponding j(formate) ranging from -13.76 to -44.89 mA cm(-2). Moreover, the maximum FE(formate )reaches 94.6% at -1.0 V versus RHE with j(formate) of -32.2 mA cm(-2). The catalyst also shows good long-term stability. The re-Bi NSs in a flow cell achieved a FEformate of 94.6% with a high current density of -400.0 mA cm(-2). Our new strategy for the preparation of a catalyst with a reconstituted Bi-0 atom will provide a novel tool for the design of highly active and stable Bi-based electrocatalysts.