Au nanoparticles and fine Ta2O5 nanocrystallines were deposited on nonaggregated, spherical, monodisperse SiO2 micorspheres to form a kind of sandwiched core-shell structured SiO2 Au Ta2O5 composite plasmonic photocatalyst by an in-situ reduction process integrated with a sol-gel process. The prepared SiO2 Au Ta2O5 composite plasmonic photocatalyst was nitrided in ammonia flow at an appropriate temperature to obtain SiO2 Au Ta3N5 composite plasmonic photocatalyst. Benefitting from Au nanoparticles' surface plasmon resonance effect, the obtained SiO2 Au Ta2O5 composite plasmonic photocatalyst presents a novel photochemical activity of H2 production from H2O with visible light response, and the prepared SiO2 Au Ta3N5 composite plasmonic photocatalyst exhibits a higher photochemical activity of H2 production from H2O with visible light response than that of blank Ta3N5 nanocrystalline. Furthermore, the excellent morphologies of SiO2 Au Ta2O5 and SiO2 Au Ta3N5 composites, e.g., sandwiched core-shell structure, monodisperse, and spherical, drastically improve their dispersion in solution, light harvesting, charge separation and transportation, which might do some contributions to improve their photocatalytic activities accordingly. This investigation might set a good example for designing highly efficient plasmonic photocatalysts for photochemical solar H2 production with visible light response.
