School of Environment, Henan Key Laboratory for Environmental Pollution Control, Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, 453007, Henan, People's Republic of China.
Environ Sci Pollut Res Int. 2017 Oct;24(29):23309-23320. doi: 10.1007/s11356-017-9969-2. Epub 2017 Aug 24.
In this work, visible light-responsive carbon nanotubes (CNTs)/BiVOCl composite photocatalysts have been prepared by a facile in situ hydrothermal method and characterized by various techniques. The photocatalytic properties of the photocatalysts are evaluated by the degradation of refractory azo-dye methyl orange (MO), hexavalent chromium Cr(VI), and bisphenol A (BPA) in water under visible light irradiation. It is found that the as-prepared composite with 4 wt% CNTs shows an optimal photocatalytic performance, and its photocatalytic activity is 30% higher than that of pure BiVOCl. The enhanced photocatalytic activity is ascribed to the synergetic effects induced by increased light absorption, increased adsorption efficiency for pollutant, and suppressed recombination rate of photogenerated charge carriers. Furthermore, efficient removals of Cr(VI), bisphenol A (BPA), and combined contamination of Cr(VI) and BPA over CNTs/BiVOCl composite further confirm that the degradation of organic pollutants is a photocatalytic mechanism rather than photosensitization of dye. Of particular importance is that removal efficiency of single pollutant can be promoted by the coexistence of the Cr(VI) and organics. The mechanism of synergetic promotion is discussed and attributed to the accelerated separation of charge carriers resulted from their simultaneously being captured by pollutants. Moreover, the CNTs/BiVOCl composite exhibits good stability and recycling performance in the photocatalytic degradation process. Therefore, the composite photocatalysts developed in the present work are expected to have the potential in purification of complex wastewater. Graphical abstract The separation of photogenerated charge carriers and adsorbing capacity as well as visible light absorption ability of BiVOCl are significantly promoted by coupling with carbon nanotubes. Simultaneous removal of Cr(VI) and organic pollutants can be achieved by CNTs/BiVOCl composite photocatalysts under visible light irradiation.
在这项工作中，通过简便的原位水热法制备了可见光响应的碳纳米管（CNTs）/BiVOCl 复合光催化剂，并通过各种技术对其进行了表征。通过在可见光照射下水中难处理偶氮染料甲基橙（MO）、六价铬 Cr(VI)和双酚 A（BPA）的降解来评估光催化剂的光催化性能。结果发现，制备的含 4wt%CNTs 的复合材料表现出最佳的光催化性能，其光催化活性比纯 BiVOCl 高 30%。增强的光催化活性归因于增加的光吸收、增加的污染物吸附效率和抑制光生载流子复合速率引起的协同效应。此外，CNTs/BiVOCl 复合材料对 Cr(VI)、双酚 A（BPA）和 Cr(VI)和 BPA 复合污染物的有效去除进一步证实了有机污染物的降解是一种光催化机制，而不是染料的光敏化。特别重要的是，单一污染物的去除效率可以通过 Cr(VI)和有机物的共存而得到促进。讨论了协同促进的机制，并归因于污染物同时捕获导致载流子分离加速。此外，在光催化降解过程中，CNTs/BiVOCl 复合材料表现出良好的稳定性和可回收性能。因此，本工作中开发的复合光催化剂有望在复杂废水净化方面具有潜力。
