Zhang Wen-Hai, Ji Qing-Hua, Lan Hua-Chun, Li Jing
School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China.
Center for Water and Ecology, Tsinghua University, Beijing 100084, China.
Huan Jing Ke Xue. 2019 Mar 8;40(3):1295-1301. doi: 10.13227/j.hjkx.201808239.
The separation efficiency of photogenerated electrons and holes is the key to photocatalytic performance. Layered BiOCl is a kind of newly exploited efficient photocatalyst, but its wide-spread practical application is hindered by the rapid recombination of photogenerated electron-hole pairs and low quantum efficiency. In this study, we prepared a composite photocatalyst via a hydrothermal method in which (NH)PWO (NHPTA) is the acceptor of photoelectrons from BiOCl. The photocatalytic performance of variants of BiOCl-NHPTA was evaluated by the removal efficiency of methyl orange (MO). The experimental results showed that the BiOCl-NHPTA[ (Bi): (W)=1:1] had the best photocatalytic activity under the irradiation of sunlight simulated by xenon light. The photocatalytic mechanism was investigated using the reactive species trapping experiments. It was found that MO could be photodegraded by,·OH, and holes over BiOCl. Differently, and·OH were the dominant reactive species for the reactions over the composite photocatalyst. It was proved that NHPTA was the acceptor of photoelectrons by the XPS on the photocatalyst before and after reaction. The photocurrent test verified the superior photocatalysis of BiOCl-NHPTA which was attributed to the efficient separation of electron-hole pairs.
光生电子和空穴的分离效率是光催化性能的关键。层状BiOCl是一种新开发的高效光催化剂，但其光生电子 - 空穴对的快速复合和低量子效率阻碍了其广泛的实际应用。在本研究中，我们通过水热法制备了一种复合光催化剂，其中(NH)PWO (NHPTA)是BiOCl光电子的受体。通过甲基橙(MO)的去除效率评估了BiOCl - NHPTA变体的光催化性能。实验结果表明，BiOCl - NHPTA[(Bi):(W)=1:1]在氙灯模拟的太阳光照射下具有最佳的光催化活性。利用活性物种捕获实验研究了光催化机理。发现MO可被BiOCl上的·OH和空穴光降解。不同的是，·O₂⁻和·OH是复合光催化剂反应中的主要活性物种。通过反应前后光催化剂的XPS证明NHPTA是光电子的受体。光电流测试验证了BiOCl - NHPTA优异的光催化性能，这归因于电子 - 空穴对的有效分离。
