A Facile Design for Water‐Oxidation Molecular Catalysts Precise Assembling on Photoanodes

Abstract Regulating the interfacial charge transfer behavior between cocatalysts and semiconductors remains a critical challenge for attaining efficient photoelectrochemical water oxidation reactions. Herein, using bismuth vanadate (BiVO₄) photoanode as a model, it introduces an Au binding bridge as holes transfer channels onto the surfaces of BiVO₄, and the cyano‐functionalized cobalt cubane (Co₄O₄) molecules are preferentially immobilized on the Au bridge due to the strong adsorption of cyano groups with Au nanoparticles. This orchestrated arrangement facilitates the seamless transfer of photogenerated holes from BiVO₄ to Co₄O₄ molecules, forming an orderly charge transfer pathway connecting the light‐absorbing layer to reactive sites. An exciting photocurrent density of 5.06 mA cm⁻² at 1.23 V versus the reversible hydrogen electrode (3.4 times that of BiVO₄) is obtained by the Co₄O₄@Au(A)/BiVO₄ photoanode, where the surface charge recombination is almost completely suppressed accompanied by a surface charge transfer efficiency over 95%. This work represents a promising strategy for accelerating interfacial charge transfer and achieving efficient photoelectrochemical water oxidation reaction.