Ultrafast Electron Transfer at BiVO 4 ‐VO x Z‐Scheme Interface for Enhanced Selective Oxidation of Glycerol to Dihydroxyacetone

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ABSTRACT Photoelectrochemical (PEC) selective oxidation of glycerol offers a sustainable strategy to obtain dihydroxyacetone (DHA) as a value‐added chemical, which remains challenging owing to the slow kinetics and low selectivity. We construct a Z‐scheme heterojunction consisting of an amorphous vanadium oxide nanolayer on BiVO 4 nanoparticles (BiVO 4 ‐VO x ) for glycerol oxidation by a spatially confined photoelectron deposition method. BiVO 4 ‐VO x photoanode achieves a high DHA evolution rate of 400.4 mmol m −2 h −1 and a selectivity of 65.6% at 1.2 V vs. RHE. Femtosecond transient absorption spectroscopy analysis demonstrates superior charge separation efficiency and ultrafast interfacial transfer kinetics, enabling long‐lived photogenerated electrons and holes accumulated in BiVO 4 conduction band and VO x valence band, respectively. Furthermore, in situ Fourier transform infrared spectroscopy and theoretical calculations reveal that the synergy between the optimized electronic structure of amorphous VO x and Z‐scheme heterojunction promotes preferential adsorption of glycerol middle hydroxyl groups and lowers the energy barrier of the rate‐determining step, thus facilitating selective DHA production. We fabricated a self‐powered device with a DHA productivity of 122.0 mmol m −2 h −1 , a H 2 productivity of 1.33 mL cm −2 h −1 and a solar‐to‐H 2 conversion efficiency of 4.7%. This work highlights the potential of heterojunction engineering for PEC biomass valorization toward value‐added products.

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