摘要
TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the alcohol system,and then the TiO2nanoparticles(NPs)grew on the WS2/g-C3N4nano-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-C3N4and TiO2/g-C3N4composite.The enhanced photocatalytic activities of TiO2/WS2/g-C3N4photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2NPs and WS2/g-C3N4nano-sheets,which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons.The quenching tests of radicals indicated that?O2?had crucial effect on degradation of MO,which demonstrated that?O2?was the main active radical in photocatalytic reaction process.
采用液相剥离和溶剂热法制备TiO_2/WS_2/g-C_3N_4复合光催化剂。通过液相剥离的方法在乙醇体系中将块状WS_2和C_3N_4剥离得到相应的纳米片;利用热处理法使TiO_2纳米粒子原位生长并固定于WS_2/g-C_3N_4纳米片上。采用光催化降解甲基橙(MO)来评价TiO_2/WS_2/g-C_3N_4的光催化活性。结果表明,TiO_2/WS_2/g-C_3N_4复合光催化剂的光催化活性远高于纯态TiO_2,g-C_3N_4及TiO_2/g-C_3N_4复合物,这主要归因于WS_2/g-C_3N_4杂化复合物与TiO_2纳米粒子之间的协同作用,有效促进了复合光催化剂中光生电子/空穴对的分离,提高了光子的利用率。活性自由基的捕获实验表明,·O_2^-对MO的降解起着决定性的作用,这说明·O_2^-是光催化反应过程中主要的活性自由基。
基金
Projects(21376099,21546002)supported by the National Natural Science Foundation of China
