BiPO₄ -Derived 2D Nanosheets for Efficient Electrocatalytic Reduction of CO₂ to Liquid Fuel

The electrochemical reduction of carbon dioxide (CO₂ ) to high-value liquid fuel with high selectivity is appealing for energy conversion and storage. Here we report a bismuth phosphate (BiPO₄ ) derived 2D nanosheet-like electrocatalyst that efficiently converts CO₂ into liquid-phase formate. The catalyst presents a formate Faradaic efficiency of over 90 % and a cathodic energy efficiency of 73 % at an industrially relevant current density of 200 mA cm^-2 in the flow cell. The in situ generation of the Bi-O active species on the catalyst surface was determined via operando Raman measurement. Morphological and X-ray photoelectron spectroscopy analyses reveal the origin of the high activity for the electrosynthesis of formate from CO₂ and water: the 2D structure together with the abundant insertion of oxygen atoms in the surface of the BiPO₄ -derived nanosheets.