Constructing BiVO4-Au@CdS photocatalyst with energic charge-carrier separation capacity derived from facet induction and Z-scheme bridge for degradation of organic pollutants

A rational design and precise control over charge carriers transportation in Z-scheme system is favorable for achieving its optimal photocatalytic performance. Herein, a ternary composite Z-scheme photocatalyst with Au@CdS selectively deposited on the {010} facets of BiVO4 was prepared. Due to the fact that the CB edge and VB edge of the {110} facet of BiVO4 are higher than those of its {010} facet, the photo-generated electrons and holes in well-faceted BiVO4 transferred to the {010} and {110} facets, respectively. The electrons on the {010} facets of BiVO4 transferred through Au NPs as the electron mediator to combine with holes of CdS at the interface. Benefiting from the dual-facilitated charge carriers transportation in Z-scheme and well-faceted BiVO4 crystals, the photocatalytic efficiency of the optimal ternary BiVO4-Au@CdS hybrids is 6.11, 3.03 and 2.95 times higher than those of BiVO4, BiVO4-Au and BiVO4-CdS toward Rhodamine B degradation and 1.46 times higher than that of BiVO4 (random facets)-Au@CdS toward 4-nonylphenol degradation. This work provides a new insight on rational design of Z-scheme system based on well-faceted nanocrystals for enhancing photocatalytic performance.