Enhanced photoelectrochemical water oxidation over a surface-hydroxylated BiVO₄photoanode: advantageous charge separation and water dissociation

Abstract

Bismuth vanadate (BiVO4) is one of the most effective photoanode materials for photoelectrochemical water splitting, while its reaction rate is greatly limited by the poor separation efficiency of photo-generated charges...

Surface Hydroxylation during Water Splitting Promotes the Photoactivity of BiVO4(010) Surface by Suppressing Polaron-Mediated Charge Recombination

“…The dissociation of surface water (leading to surface hydroxyl) on BiVO 4 increases the complexity of reactions and has a profound impact on the formation of surface polaron and carrier dynamics. For instance, Li et al discovered that surface hydroxylation of the BiVO 4 photoanode improves photogenerated charges separation, resulting in an increase in photocurrent density by 4.75 times . By using ambient pressure resonant photoemission spectroscopy combined with first-principles calculations, Wang et al reported that dissociated water molecules caused hydroxylation of VO 4 tetrahedron on BiVO 4 (010), leading to an enhanced stability of the surface polarons and an alternation of the surface electronic structure .…”

“…For instance, Li et al discovered that surface hydroxylation of the BiVO 4 photoanode improves photogenerated charges separation, resulting in an increase in photocurrent density by 4.75 times. 27 By using ambient pressure resonant photoemission spectroscopy combined with first-principles calculations, Wang et al reported that dissociated water molecules caused hydroxylation of VO 4 tetrahedron on BiVO 4 (010), leading to an enhanced stability of the surface polarons and an alternation of the surface electronic structure. 28 Surface hydroxylation of metal oxides is commonly observed in the photocatalytic water decomposition process; however, the effect of surface hydroxylation on polaron dynamics is still a mystery and requires a detailed time-domain study of the polaron coupled charge carrier dynamics.…”