Ren Ting, Jin Zehua, Yang Jun, Hu Ruisheng, Zhao Fu, Gao Xiaojiao, Zhao Chunxiao
Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, Inner Mongolia, China.
Key Laboratory of Coal Chemistry, School of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, Inner Mongolia, China.
J Hazard Mater. 2019 Sep 5;377:195-205. doi: 10.1016/j.jhazmat.2019.05.070. Epub 2019 May 27.
A series of catalysts with p-LaFeO/n-ZnO heterostructure were designed and prepared by hydrothermal method. The structure, surface topographies, optical properties and interfacial interactions of these photocatalysts were analyzed by XRD, SEM, TEM, PL, Uv-vis DRS, XPS, COD, TOC etc., indicating that p-n heterojunction formed at the interface between p-LaFeO and n-ZnO, which enhanced the photocatalytic activity. Among them, the 20%-p-LaFeO/n-ZnO composite exhibits the best activity for the phenol degradation under visible light. The superior photocatalytic activity of the heterojunction photocatalyst is mainly attributed to the formation of p-n heterojunction which leads to an efficient separation of photogenerated electron-hole pairs. Besides, the 20%-p-LaFeO/n-ZnO heterojunction photocatalyst shows the excellent photocatalytic stability after 4 cycles. And from the free radical capture experiment, the degradation of phenol is dominated by the oxidation reaction of hydroxyl radicals and direct hole oxidation. What's more, certain intermediates were detected by HPLC and 3D-EEMs. Therefore, a photocatalytic mechanism of the 20%-p-LaFeO/n-ZnO p-n heterojunction catalyst for phenol degradation under visible light irradiation was proposed.
采用水热法设计并制备了一系列具有p-LaFeO/n-ZnO异质结构的催化剂。通过XRD、SEM、TEM、PL、Uv-vis DRS、XPS、COD、TOC等对这些光催化剂的结构、表面形貌、光学性质和界面相互作用进行了分析，表明在p-LaFeO与n-ZnO的界面处形成了p-n异质结，从而提高了光催化活性。其中，20%-p-LaFeO/n-ZnO复合材料在可见光下对苯酚降解表现出最佳活性。异质结光催化剂优异的光催化活性主要归因于p-n异质结的形成，导致光生电子-空穴对的有效分离。此外，20%-p-LaFeO/n-ZnO异质结光催化剂在4次循环后表现出优异的光催化稳定性。通过自由基捕获实验可知，苯酚的降解主要由羟基自由基的氧化反应和直接空穴氧化作用主导。更重要的是，通过HPLC和3D-EEMs检测到了某些中间产物。因此，提出了20%-p-LaFeO/n-ZnO p-n异质结催化剂在可见光照射下对苯酚降解的光催化机理。
