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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。
TiO 2 / WS 2 / g-C 3 N 4 composite photocatalyst was prepared by liquid phase separation and solvothermal method. The strip-like WS_2 and C_3N_4 were peeled off from ethanol solution to obtain the corresponding nanosheets. The TiO_2 nanoparticles were grown in situ and immobilized on WS_2 / g-C_3N_4 nanosheets by thermal treatment. Photocatalytic degradation of methyl orange (MO) was used to evaluate the photocatalytic activity of TiO_2 / WS_2 / g-C_3N_4. The results show that the photocatalytic activity of TiO_2 / WS_2 / g-C_3N_4 composite photocatalyst is much higher than that of pure TiO_2, g-C_3N_4 and TiO_2 / g-C_3N_4 composites, which is mainly attributed to the hybrid of WS_2 / g-C_3N_4 And the synergetic effect between TiO 2 nanoparticles can effectively promote the separation of photogenerated electron / hole pairs in the composite photocatalyst and improve the utilization of photons. The experiments on the capture of living free radicals showed that O 2 - played a decisive role in the degradation of MO, which indicated that O 2 - was the main active radical in the photocatalytic reaction.