Construction of heterostructured g-C₃N₄/Ag/TiO₂ microspheres with enhanced photocatalysis performance under visible-light irradiation.

The visible-light photocatalytic performance of the heterostructured g-C3N4/Ag/TiO2 microspheres was investigated. As an electron-conduction bridge, Ag nanoparticles were photodeposited as the interlayer between g-C3N4 and the surface of TiO2 microspheres to increase visible-light absorption via the surface plasmon resonance. The interface between Ag/TiO2 and g-C3N4 facilitates the direct migration of photoinduced electrons from g-C3N4 to Ag/TiO2, which is conductive to retarding the recombination of electron-holes. The g-C3N4 (4%)/Ag/TiO2 microsphere sample shows significant photocatalytic activity, higher than the sum of g-C3N4 (1.2 mg) and Ag/TiO2 samples, or the sum of TiO2 and Ag/g-C3N4 (1.8 mg) samples. It indicates that the heterostructured combination of g-C3N4, Ag and TiO2 microspheres provides synergistic photocatalytic activity through an efficient electron transfer process.