Crystal-facet-dependent hot-electron transfer in plasmonic-Au/semiconductor heterostructures for efficient solar photocatalysis

Here, using Au-BiOCl as models, we show the significant crystal facet effects of the semiconductor on hot-electron transfer within such plasmonic heterostructures under visible light. It is found that {010} facets of BiOCl are greatly advantageous over {001} facets for the hot-electron injection, as evidenced by steady-state diffuse reflectance spectroscopy and photoelectrochemical measurements. Consequently, Au-BiOCl-010 exhibits superior activity for photocatalytic aerobic oxidation of 2-propanol with a quantum efficiency of 1.3%, being 3.5 times higher than that of Au-BiOCl-001. The differences in band structure between the {001} and {010} facets of BiOCl may account for the facet-dependent hot-electron transfer characteristics.