Plasmonic Z-scheme Pt-Au/BiVO4 photocatalyst: Synergistic effect of crystal-facet engineering and selective loading of Pt-Au cocatalyst for improved photocatalytic performance

Abstract Constructing Z-scheme photocatalysts is one of the most effective technologies to enhance the photocatalytic reduction or oxidation ability in artificial photosynthesis. For the BiVO4 photocatalyst, it usually shows limited photocatalytic ability because of the severe bulk recombination of photogenerated carriers and the poor reduction reaction of photogenerated electrons. In this paper, a novel plasmonic Z-scheme Pt-Au/BiVO4 single-crystal photocatalyst was constructed to solve the above issues. Here, Au nanoparticles are selectively deposited on the electron-rich (010) facet of BiVO4, while Pt nanoparticles are selectively modified on the Au surface. Photocatalytic results indicated that the resultant Pt-Au/BiVO4 Z-scheme photocatalyst exhibits an obviously higher photocatalytic performance than pure BiVO4, Au/BiVO4, randomly deposited BiVO4(Pt-Au/BiVO4(R)) and conventional Pt-Au/BiVO4. More importantly, compared with the well-known Pt/BiVO4(2.0 wt%), the Pt-Au/BiVO4 not only exhibits a higher photocatalytic performance, but also loads a lower amount of high-cost Pt cocatalyst. The excellent photocatalytic activity of the plasmonic Z-scheme Pt-Au/BiVO4 photocatalyst can be attributed to the synergistic effect of crystal-facet engineering and selective loading of Pt-Au, which results in the orientation transfer of photogenerated carriers in the single-crystal BiVO4, the enhanced reduction power of photogenerated electrons, and the rapid oxygen-reduction reaction on Pt cocatalyst.