WS2/g-C3N4异质结光催化分解水制氢性能及机制

通过溶剂蒸发和二次高温煅烧石墨相碳化氮(g-C₃N₄)纳米片和WS₂纳米片混合物构建WS₂/g-C₃N₄异质结，该异质结保留g-C₃N₄和WS₂主体结构的同时，在界面处形成化学键，确保该异质结的化学稳定性和热稳定性。光催化分解水制氢实验表明，WS₂纳米片含量为3wt%时光催化制氢速率高达68.62 μmol/h，分别是g-C₃N₄纳米片和WS₂纳米片的2.53倍和15.29倍，表明异质结的构建可大幅提升g-C₃N₄的光催化性能，循环实验表明该异质结在5次循环实验后光催化性能没有明显下降，表明该异质结的稳定性较好。光电性能测试表明异质结的构建不仅提高激发电子的转移效率，同时抑制激发电子空穴的复合率，大幅提升激发电子的利用效率，致使光催化分解水制氢速率较g-C₃N₄纳米片和WS₂纳米片大幅提升。 

H production performance of photocatalyst and mechanism of WS2/g-C3N4 heterojunction

The WS₂/graphite phase nitrogen carbide(g-C3 N4) heterojunction was established through the solvent evaporation and second calcinations the mixture of g-C₃N₄nanosheets and WS₂ nanosheets. The main structure of g-C₃N₄and WS₂ in the heterojunction is not destroyed in the calcinations process and the interface is connected by chemical bond, which enhances the stability of heterojunction. The photocatalysis results indicate that the H₂ production rate reaches to 68.62 μmol/h while the content of WS₂ is 3 wt%, which are 2.53 times and 15.29 times as that of g-C₃N₄nanosheets and WS₂ nanosheets, respectively. Besides, the H₂ production rate is not decreased distinctly after 5 times circulation experiments, which reveals that the WS₂/g-C₃N₄heterojunction has a good chemical stability. Photoelectric property indicates that the establish of heterojunction structure can not only enhance the transport rate of excited electrons, but also suppress the recombination rate of charge carriers. Thus, the H₂ production rate is enhanced distinctly compared with that of pure g-C₃N₄nanosheets and WS₂ nanosheets.