Energy Transfer‐Induced Photoelectrochemical Improvement from Porous Zeolitic Imidazolate Framework‐Decorated BiVO₄ Photoelectrodes

Abstract BiVO₄, which is a representative photoanode material for photoelectrochemical water splitting, intrinsically restricts high conversion efficiency, owing to faster recombination, low electron mobility, and short electron diffusion length. While the photocurrent density of typical BiVO₄ corresponds to only 21.3% of the maximum photocurrent density (4.68 mA cm⁻²), decoration of the BiVO₄ photoanode with zeolitic imidazolate framework‐67 (ZIF‐67) exhibits a synergetic effect to raise the overall photocatalytic ability at the BiVO₄ surface region to a higher level via the energy‐transfer process from BiVO₄ to ZIF‐67. The hybrid ZIF‐67/BiVO₄ photoanode follows two convenient photoelectrochemical pathways: 1) energy‐transfer‐induced water oxidation reaction in ZIF‐67 and 2) water oxidation reaction by direct contact between the BiVO₄ surface and electrolytes. Compared to the moderate photocurrent density (≈1 mA cm⁻²) of single‐layer BiVO₄, the proposed ZIF‐67/BiVO₄ photoanodes show a remarkably high photocurrent (2.25 mA cm⁻²) with high stability, despite the lack of hole scavengers in the electrolyte. Furthermore, the absorbed photon‐to‐current efficiency of the ZIF‐67/BiVO₄ photoanode is ≈2.5 times greater than that of BiVO₄. This work proposes a promising solution for efficient water oxidation that overcomes the intrinsic material limitations of BiVO₄ photoelectrodes by using energy transfer‐induced photon recycling and the decoration of porous ZIFs.