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 ·O^?₂ had crucial effect on degradation of MO, which demonstrated that ·O^?₂ was the main active radical in photocatalytic reaction process.