Enhanced photocatalytic activity of TiO2 nanoparticles using WS2/g-C3N4 hybrid as co-catalyst

TiO2/WS2/g-C3N4 composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method. In this process, the WS2/g-C3N4 nano-sheets were prepared by liquid-exfoliation method from the bulk WS2 and C3N4 in the alcohol system, and then the TiO2 nanoparticles (NPs) grew on the WS2/g-C3N4 nano-sheets by in-situ synthesized technique. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange (MO). The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO2, g-C3N4 and TiO2/g-C3N4 composite. The enhanced photocatalytic activities of TiO2/WS2/g-C3N4 photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2 NPs and WS2/g-C3N4 nano-sheets, which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons. The quenching tests of radicals indicated that center dot O-2(-). had crucial effect on degradation of MO, which demonstrated that center dot O-2(-). was the main active radical in photocatalytic reaction process.