Enhanced photocatalytic activities of single-crystalline ZnGa2O4 nanoprisms by the coexposed {111} and {110} facets

Facet-control has been a fascinating method for preparation of highly active photocatalysts. Herein, we report the hydrothermal preparation of single-crystalline ZnGa2O4 nanoprisms with the {111} and {110} facets coexposed. Studies of their photocatalytic performance have revealed that the as-formed nanoprisms exhibit significantly enhanced photocatalytic activities compared with ZnGa2O4 nanocubes with only the {100} facets exposed and nanosheets with the {110} facets exposed for H-2 evolution and contaminant degradation. Theoretical calculations combined with valence band XPS results indicate the formation of a surface heterojunction by the coexposed {111} and {110} facets, which promotes the photogenerated electron and hole migration to the {110} and {111} facets, respectively, and enhances the photocatalytic performance.