Guan Yu, Liu Yinhe, Lv Qiang, Wu Jiang
State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China; College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090, China.
State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
J Hazard Mater. 2021 Sep 15;418:126280. doi: 10.1016/j.jhazmat.2021.126280. Epub 2021 Jun 2.
Photocatalytic oxidation method is a promising technology for solving flue gas mercury (Hg) pollution from industrial plants. Semiconductor photocatalysts have been widely applied in energy conversion and environmental remediation. However, key issues such as low light absorption capacity, wide energy band gap, and poor physicochemical stability severely limit the application of photocatalysts in practical industrial plants. In recent years, bismuth-based (Bi-based) photocatalysts, including bismuth oxide halide BiOX (X = Cl, Br or I), bismuth salt oxymetal BiVO, and BiOIO etc., have increasingly aroused scientists' attention due to their peculiar crystalline geometric structures, tunable electronic structure and high photocatalytic performance. In present review, we firstly review the photocatalytic reaction mechanism and main photocatalytic oxidation mechanism of mercury. Secondly, the synthetic methods of Bi-based photocatalysts are summarized. Then, according to the mechanism of mercury removal, the experimental modifying approaches including heterojunction making, external atoms doping, defect creating, and crystal face regulating to promote the photocatalytic oxidation of mercury removal are summarized, as well as the determination of the band gap and electronic density of states (DOS) of Bi-based photocatalysts to elucidate the photocatalytic oxidation mechanism via density functional theory (DFT) calculation. Furthermore, constructing electronic transmission channels is an efficient way to improve the photocatalytic activity. Finally, challenges and perspectives of Bi-based photocatalyst for photocatalytic oxidation of mercury removal are presented. In addition, the excellent performance photocatalysts and efficient pollution removal equipment for mercury removal in industrial plants are still required in-depth study.
光催化氧化法是解决工业工厂烟气汞(Hg)污染的一项很有前景的技术。半导体光催化剂已广泛应用于能量转换和环境修复。然而,诸如光吸收能力低、能带隙宽和物理化学稳定性差等关键问题严重限制了光催化剂在实际工业工厂中的应用。近年来,铋基(Bi基)光催化剂,包括卤氧化铋BiOX(X = Cl、Br或I)、氧金属铋盐BiVO以及BiOIO等,因其独特的晶体几何结构、可调谐的电子结构和高光催化性能而越来越引起科学家的关注。在本综述中,我们首先回顾汞的光催化反应机理和主要光催化氧化机理。其次,总结了Bi基光催化剂的合成方法。然后,根据汞去除机理,总结了包括异质结制备、外部原子掺杂、缺陷形成和晶面调控等促进汞去除光催化氧化的实验改性方法,以及通过密度泛函理论(DFT)计算确定Bi基光催化剂的带隙和电子态密度(DOS)以阐明光催化氧化机理。此外,构建电子传输通道是提高光催化活性的有效途径。最后,介绍了Bi基光催化剂用于汞去除光催化氧化的挑战和前景。此外,工业工厂中用于汞去除的优异性能光催化剂和高效污染去除设备仍需深入研究。