Preparation and characterization of g-C3N4/Ag–TiO2 ternary hollowsphere nanoheterojunction catalyst with high visible light photocatalytic performance

Abstract

In this work, a g-C3N4/Ag–TiO2 ternary heterogeneous photocatalyst with a hollow nanosphere structure was prepared by combining small g-C3N4 nanosheets and hollow Ag–TiO2 spheres. The results show that at an Ag deposition of 2% (mass ratio to pure TiO2), the resulting 2%-AgTCN exhibits the best degradation performance, reaching a photodegradation efficiency of 92.7% for RhB. This is 3.10 and 2.15 times that of pure TiO2 and g-C3N4, respectively. The main sources of the excellent photocatalytic performance are as follows: (1) The Ag deposited between TiO2 hollow spheres and g-C3N4 nanosheets promotes the transfer of interfacial electrons in the composite, effectively overcoming the rapid recombination of electron-hole pairs. (2) The disordered g-C3N4 nanosheets coated on the surface of hollow Ag–TiO2 spheres are small, with a side length of approximately 30–100 nm, which increases the heterogeneous interface area. (3) The special hollow sphere structure endows the catalyst with a more efficient light-capturing ability.