Electron‐Rich Bi Nanosheets Promote CO2⋅− Formation for High‐Performance and pH‐Universal Electrocatalytic CO2 Reduction

Abstract

AbstractElectrochemical CO2 reduction reaction (CO2RR) to chemical fuels such as formate offers a promising pathway to carbon‐neutral future, but its practical application is largely inhibited by the lack of effective activation of CO2 molecules and pH‐universal feasibility. Here, we report an electronic structure manipulation strategy to electron‐rich Bi nanosheets, where electrons transfer from Cu donor to Bi acceptor in bimetallic Cu−Bi, enabling CO2RR towards formate with concurrent high activity, selectivity and stability in pH‐universal (acidic, neutral and alkaline) electrolytes. Combined in situ Raman spectra and computational calculations unravel that electron‐rich Bi promotes CO2⋅− formation to activate CO2 molecules, and enhance the adsorption strength of *OCHO intermediate with an up‐shifted p‐band center, thus leading to its superior activity and selectivity of formate. Further integration of the robust electron‐rich Bi nanosheets into III–V‐based photovoltaic solar cell results in an unassisted artificial leaf with a high solar‐to‐formate (STF) efficiency of 13.7 %.