猝灭(荧光)
光催化
氯化物
化学
激进的
废水
降级(电信)
光化学
污染物
环境化学
无机化学
环境工程
有机化学
催化作用
荧光
环境科学
物理
电信
量子力学
计算机科学
作者
Yinghua Chi,Shiping Xu,Mingxue Li,Maoxia He,Haiyan Yu,Li Li
标识
DOI:10.1016/j.jhazmat.2020.122670
摘要
Photocatalytic degradation of pollutants in high salinity wastewater usually shows extremely low activities and produces highly toxic by-products, often related to the presence of excess chloride ion (Cl−). Herein, we report for the first time that involvement of Cl− (quenching active species and generating chlorinated by-products) could be effectively blocked during photocatalytic processes. Based on a comprehensive investigation of its mechanism, we found that Cl− could quench superoxide radicals (O2−) through a cyclic indirect quenching model with holes (h+) and hydroxyl radicals (OH) quenching as "initiators". Thus, scavenging h+ and OH could successfully block the chain reactions between Cl− and O2−, and photocatalytic degradation of methyl orange (a refractory dye, with O2− as dominant attacking species) could be enhanced by nearly 50 times, even when Cl− content was up to 10 wt%. More importantly, both HPLC-MS analyses and DFT calculation validated that, by blocking its quenching effect, Cl− could be successfully excluded from the pollutant degradation processes, thus preventing the generation of toxic chlorinated by-products. This work provides new insights into control of chlorinated by-products and proposes feasible strategies to extend photocatalytic technology in high salinity wastewater.
科研通智能强力驱动
Strongly Powered by AbleSci AI