College of Civil Engineering, Fuzhou University, 350116 Fujian, PR China; State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, 350002 Fujian, PR China; Fujian Provincial Key Laboratory of Electrochemical Energy Storage Materials, Fuzhou University, 350002 Fujian, PR China.
College of Civil Engineering, Fuzhou University, 350116 Fujian, PR China.
J Hazard Mater. 2021 May 5;409:125018. doi: 10.1016/j.jhazmat.2020.125018. Epub 2020 Dec 31.
A novel plasmonic Ag/AgCl@LaFeO (ALFO) photocatalyst was successfully synthesized by a simple in-situ synthesis method with enhanced photocatalytic activity under visible light for harmful algal blooms (HABs) control. The structure, morphology, chemical states, optical and electrochemical properties of the photocatalyst were systematically investigated using a series of characterization methods. Compared with pure LaFeO and Ag/AgCl, ALFO-20% owned a higher light absorption capacity and lower electron-hole recombined rate. Therefore, ALFO-20% had higher photocatalytic activity with a near 100% removal rate of chlorophyll a within 150 min, whose kinetic constant was 15.36 and 9.61 times faster than those of LaFeO and Ag/AgCl. In addition, the changes of zeta potential, cell membrane permeability, cell morphology, organic matter, total soluble protein, photosynthetic system and antioxidant enzyme system in Microcystis aeruginosa (M. aeruginosa) were studied to explore the mechanism of M. aeruginosa photocatalytic inactivation. The results showed that ALFO-20% could change the permeability and morphology of the algae cell membrane, as well as destroy the photosynthesis system and antioxidant system of M. aeruginosa. What's more, ALFO could further degrade the organic matters flowed out after algae rupture and die, reducing the secondary pollution and avoiding the recurrence of HABs. Finally, the species of reactive oxygen species (ROS) (mainly •O and •OH) produced by ALFO were determined through quenching experiments, and a possible photocatalytic mechanism was proposed. Overall, ALFO can efficiently remove the harmful algae under the visible light, providing a promising method for controlling HABs.
一种新型等离子体 Ag/AgCl@LaFeO（ALFO）光催化剂通过简单的原位合成方法成功合成，在可见光下具有增强的光催化活性，可用于控制有害藻华（HABs）。使用一系列表征方法系统研究了光催化剂的结构、形态、化学状态、光学和电化学性质。与纯 LaFeO 和 Ag/AgCl 相比，ALFO-20%具有更高的光吸收能力和更低的电子-空穴复合率。因此，ALFO-20%具有更高的光催化活性，在 150 分钟内叶绿素 a 的去除率接近 100%，其动力学常数比 LaFeO 和 Ag/AgCl 快 15.36 和 9.61 倍。此外，还研究了蓝藻（M. aeruginosa）的zeta 电位、细胞膜通透性、细胞形态、有机物、总可溶性蛋白、光合作用系统和抗氧化酶系统的变化，以探讨 M. aeruginosa 光催化失活的机制。结果表明，ALFO-20%可以改变藻类细胞膜的通透性和形态，破坏 M. aeruginosa 的光合作用系统和抗氧化系统。此外，ALFO 可以进一步降解藻类破裂和死亡后流出的有机物，减少二次污染，避免 HABs 的复发。最后，通过猝灭实验确定了 ALFO 产生的活性氧（ROS）（主要为•O 和•OH）的种类，并提出了一种可能的光催化机制。总的来说，ALFO 可以在可见光下有效去除有害藻类，为控制 HABs 提供了一种有前途的方法。
