Synergy of charge pre-separation and direct Z-scheme bridge in BiVO4{0 4 0}/Ag6Si2O7 photocatalyst boosting organic pollutant degradation

The rapid recombination and poor redox capability of photoinduced charge carriers seriously impede the photocatalytic activity . Herein, a direct Z-scheme photocatalyst was fabricated by selectively depositing Ag 6 Si 2 O 7 nanoparticles (NPs) on the {0 4 0} facets of BiVO 4 . Owing to the facet-dependent band structure of BiVO 4 , the photoinduced electrons and holes can be pre-separated upon photoillumination and transfer to {0 4 0} and {1 1 0} facets of BiVO 4 , respectively. A rapid combination of the separated electrons at the {0 4 0} facets of BiVO 4 with holes of the Ag 6 Si 2 O 7 NPs then takes place triggering a direct Z-scheme photocatalysis. Such a charge pre-separation triggered by the faceted BiVO 4 , together with Z-scheme at the interface warrants not only effective photoinduced charge separation but also excellent redox capability owing to the increased redox potential. The photocatalytic rate constant of the optimum BiVO 4 {0 4 0}/Ag 6 Si 2 O 7 heterostructure is 28.2 and 17.2 times higher than those of pristine BiVO 4 and Ag 6 Si 2 O 7 , respectively. This study offers a new insight for constructing direct Z-scheme photocatalysts with high degradation efficiency based on facet-controlled crystals.