Efficient and highly selective photocatalytic reduction of Cr(Ⅵ) by an active two-dimensional covalent organic framework  

作　　者：Yuxuan Bai Yunzi Wang Junyu Chen Keda Zhu Jianjun Wang 

机构地区：[1]MOE Key Laboratory of Resources and Environmental Systems Optimization,College of Environmental Science and Engineering,North China Electric Power University,Beijing,102206,PR China

出　　处：《Progress in Natural Science:Materials International》2024年第5期933-941,共9页自然科学进展·国际材料(英文版)

基　　金：funded by National Natural Science Foundation of China (No. 22376058)

摘　　要：In this paper, a two-dimensional covalent organic framework material(named HDU-27) with thiazole structure and π-π conjugation has been successfully synthesized using the ligands tri acetaldehyde-based methoxyphenyl and benzo [1,2-d:4,5-d]thiazole-2,6-diamine in an ammonia-formaldehyde condensation reaction and applied to the photocatalytic reduction study of chromium(Cr). The photocatalytic experiments showed that HDU-27 had an excellent photocatalytic reduction of Cr(VI) with a high Cr(VI) reduction efficiency of 99.5 % at pH = 2 for 60min. In the presence of interfering ions, HDU-27 exhibited excellent selectivity for Cr(VI). Mechanistic experiments and electron spin resonance characterization identified e^(-)and ·O_(2)^(-)radicals as the main active species in Cr(VI) photocatalytic reduction. In addition, the photocatalytic rate of HDU-27 was significantly accelerated in the Cr(VI)/organic pollutant(RhB, MB, MO) mixed system due to the oxidation of the organic matter and the increase in the separation of photogenerated e^(-)-h^(+). The cycling experiments demonstrated the excellent reduction stability and recyclability of HDU-27 in the photocatalytic reduction of Cr(VI). HDU-27 is an excellent photocatalyst with potential application for removing organic pollutants and heavy metal ions from contaminated wastewater.

关 键 词：Covalent organic framework HDU-27 PHOTOCATALYSIS Chromium reduction 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学] X703[环境科学与工程—环境工程]