Li Xiuhui, Yu Zongxue, Shao Liangyan, Zeng Haojie, Liu Yuchuan, Feng Xiaofang
College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan, 610500, PR China; Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, Sichuan, 610500, PR China.
College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan, 610500, PR China; Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Chengdu, Sichuan, 610500, PR China; State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan, 610500, PR China.
J Hazard Mater. 2020 Mar 15;386:121650. doi: 10.1016/j.jhazmat.2019.121650. Epub 2019 Nov 11.
A novel strategy to construct a visible-light-driven Z-scheme heterojunction catalyst was employed by crosslinking ZnAl-layered double hydroxide (ZnAl-LDH) nanosheets with the active phase on carbon nitride (g-CN) substrates via a polydopamine bridge (a similar "bridge" structure). In this paper, multiple optical and electrochemical detection methods indicated that the 0.5P-LDH_500CN photocatalyst demonstrated excellent visible-light absorption properties, photo-generated electron-hole separation ability and photocatalytic activity for p-nitrophenol under visible-light (> 420 nm), etc. A Z-scheme charge transfer mechanism via PDA bridge was proposed to achieve heterojunction charge separation. This mechanism involved the recombination of photo-induced electrons directly on the ZnAl-LDH_500 valence band through the PDA channel and the holes were captured at the conduction band energy level of the g-CN. The detection of active species, including O-, h and OH, further proofed the Z-scheme charge transfer mechanism, which could be speculated that all active species affected the photocatalytic reaction with the order of h >OH >O-. Meanwhile, this work also exposed that the formation of active phase in ZnAl-LDH could synergize with PDA to promote the application of visible-light-active photocatalysts based on g-CN materials in high-efficiency energy.
通过聚多巴胺桥（类似的“桥”结构）将ZnAl层状双氢氧化物（ZnAl-LDH）纳米片与氮化碳（g-CN）基底上的活性相交联，采用了一种构建可见光驱动Z型异质结催化剂的新策略。本文中，多种光学和电化学检测方法表明，0.5P-LDH_500CN光催化剂在可见光（>420nm）下表现出优异的可见光吸收性能、光生电子-空穴分离能力和对对硝基苯酚的光催化活性等。提出了一种通过PDA桥的Z型电荷转移机制来实现异质结电荷分离。该机制涉及光生电子通过PDA通道直接在ZnAl-LDH_500价带上复合，空穴在g-CN的导带能级上被捕获。对包括O-、h和OH在内的活性物种的检测进一步证明了Z型电荷转移机制，可以推测所有活性物种对光催化反应的影响顺序为h>OH>O-。同时，这项工作还表明ZnAl-LDH中活性相的形成可以与PDA协同作用，促进基于g-CN材料的可见光活性光催化剂在高效能源中的应用。
