Polyhedral 30-Faceted BiVO<sub>4</sub> Microcrystals Predominantly Enclosed by High-Index Planes Promoting Photocatalytic Water-Splitting Activity.

Li, Ping; Chen, Xingyu; He, Huichao; Zhou, Xin; Zhou, Yong; Zou, Zhigang · Adv Mater · 2018

basic_science · Level V

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Abstract

Unprecedented 30-faceted BiVO<sub>4</sub> polyhedra predominantly surrounded by {132}, {321}, and {121} high-index facets are fabricated through the engineering of high-index surfaces by a trace amount of Au nanoparticles. The growth of high-index facets results in a 3-5 fold enhancement of O<sub>2</sub> evolution from photocatalytic water splitting by the BiVO<sub>4</sub> polyhedron, relative to its low-index counterparts. Theory calculations reveal that water dissociation is more energetically favorable on the high-index surfaces than on the low-index (010), (110), and (101) surfaces, which is accompanied by a notable reduction in the overpotential (0.77-1.14 V) for the oxygen evolution reaction. The apparent quantum efficiency of O<sub>2</sub> generation without an external electron supply reaches 18.3% under 430 nm light irradiation, which is an order of magnitude higher than that of the catalysts reported hitherto.