Novel β-Ag2MoO4/g-C3N4 heterojunction catalysts with highly enhanced visible-light-driven photocatalytic activity

The kernel of photocatalysis research is the development of catalysts with remarkable photocatalytic activity. g-C3N4 has attracted much interest as a new and promising photocatalyst, but further modification and improvement of g-C3N4 is urgently needed. Herein, we report a novel beta-Ag2MoO4/gC(3)N(4) heterojunction system with highly enhanced visible-light-driven photocatalytic activity. beta-Ag2MoO4 nanoparticles were in situ loaded onto thin g-C3N4 nanosheets to make these heterojunction photocatalysts. The photocatalytic activities of these heterojunctions and the relevant samples were investigated by degrading Rhodamine B (RhB), methylene blue (MB), and methyl orange (MO) under visible light irradiation (lambda > 400 nm). beta-Ag2MoO4/g-C3N4 heterojunctions were found to be much more active than pristine beta-Ag2MoO4, g-C3N4, or a mechanical mixture of both in the degradation of organic pollutants. The optimal catalyst had a beta-Ag2MoO4/g-C3N4 mass ratio of 37.5%. Through relevant characterization, the upgraded photocatalytic activities of the beta-Ag2MoO4/g-C3N4 heterojunctions were mainly attributed to the efficient separation of photogenerated charge carries. Superoxide radical anions (center dot O-2(-)) and photogenerated holes (h(+)) were found to be the main active species.