BiVO₄ Microparticles Decorated with Cu@Au Core-Shell Nanostructures for Photocatalytic H₂O₂ Production

Abstract

The nanostructured Au cocatalyst modification of BiVO4 photocatalyst, as a prospective method, can significantly promote its photocatalytic H2O2 production performance. However, the contact between Au and BiVO4 causes a strong built-in field, which impedes the photogenerated-electron transfer and the accumulation of negative charge density for Au, which reduces its catalytic activity of two-electron O2 reduction, thus limiting the enhanced H2O2 production performance of the Au/BiVO4 photocatalyst. To solve the above problems, here, a Cu@Au core-shell nanostructured cocatalyst is designed to selectively modify on the electron-enriched (010) facet of a single-crystal BiVO4 microparticle by facile photodeposition and subsequently galvanic displacement. In this case, ohmic contact between the Cu nanoparticle and (010) facet of BiVO4 can effectively transfer the photogenerated electrons to the Au cocatalyst and simultaneously facilitate the catalytic activity improvement of two-electron O2 reduction for the Au cocatalyst due to its low negative charge accumulation. As a result, the optimized BiVO4 photocatalyst with Cu@Au core-shell nanostructured modification exhibits obviously improved photocatalytic performance of H2O2 formation (91.1 μmol L–1) compared with Au/BiVO4 (62.5 μmol L–1). The present strategy of a bimetal cocatalyst with a core-shell nanostructure opens up an insight to explore effective photocatalytic materials for the application of H2O2 production.