Boosting photocatalytic water oxidation achieved by BiVO4 coupled with iron-containing polyoxometalate: Analysis the true catalyst

Abstract

In this work, BiVO4 is selected as effective light-harvesting material to replace conventional unstable dye-sensitized photosensitizer ([Ru(bpy)3]2+) that easily occurs photodecomposition during artificial photosynthetic system. The addition of an eleven iron-containing polyoxometalate (Fe11POM) as efficient cocatalyst illustrates a dramatically improved photocatalytic water oxidation performance compared with that of pure BiVO4. Through careful characterization and analysis of selected-area, highly selective in-situ photo-deposition of Fe11POM into ultrathin nanofilm on the decisive 110 facet of BiVO4 under ultrapure water is clearly observed, and an intimate connection between nanofilm and hole-rich 110 facet is obtained in favor of enhancing surface catalytic efficiency. The exquisite decoration of ultrathin nanofilm can be further clarified as FeOx decomposed from Fe11POM, which could effectively capture the photogenerated holes and suppress the recombination of electron–hole pairs for promoting water oxidation performance through fast interfacial hole transfer process.