Enhanced visible-light-driven reduction of hexavalent chromium under neutral conditions using quasi-MOF photocatalysts via thiocyanate modulation  

硫氰基改性准MOF光催化剂用于增强中性条件下六价铬的可见光还原

作　　者：Yi ZHANG Han-xiao LIAO Lu YANG Bin-hua ZHOU Xuan-zhi LIU Huan-huan ZHAI Xiao-rong HE Hong-jun HUANG Peng-fei TAN Jun PAN 张翼;廖寒潇;杨璐;周斌华;刘烜志;翟欢欢;何晓荣;黄红军;谭鹏飞;潘军(中南大学粉末冶金国家重点实验室,长沙410083;中南大学冶金与环境学院,长沙410083;长沙学院环境光催化应用技术湖南省重点实验室,长沙410022;中南大学资源加工与生物工程学院,长沙410083)

机构地区：[1]State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China [2]School of Metallurgy and Environment,Central South University,Changsha 410083,China [3]Hunan Province Key Laboratory of Applied Environmental Photocatalysis,Changsha University,Changsha 410022,China [4]School of Minerals Processing and Bioengineering,Central South University,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第11期3677-3692,共16页中国有色金属学报（英文版）

基　　金：supported by the Open Project of Yunnan Precious Metals Laboratory Co.,Ltd.,China (Nos.YPML-2023050264,YPML-2023050204);the Natural Science Foundation of Hunan Province,China (No.2022JJ40613);the National Natural Science Foundation of China (No.12074435);the Science and Technology Innovation Program of Hunan Province,China (No.2021RC4001);the Science and Technology Planning Project of Yunnan Province,China (No.202302AH360001);China Postdoctoral Science Foundation (No.2023M743941);the Postdoctoral Fellowship Program (Grade B)of China Postdoctoral Science Foundation (No.GZB20240858)。

摘　　要：In order to address the issue that the photocatalytic reduction of hexavalent chromium(Cr(VI))is often limited by the inefficient utilization of electrons in photocatalysts,a quasi-MOF photocatalyst using thiocyanate(-SCN)was developed as a modulator to enhance the charge transfer properties of ZIF-L-based photocatalysts.The incorporation of-SCN introduced structural defects,which improved visible light absorption and the reduction ability of photogenerated electrons.-SCN significantly adjusted the electronic properties and established a stable electron release pathway,serving as active sites for reduction.The optimized quasi-MOF demonstrated a Cr(VI)reduction rate of 94.8%in neutral potassium thiocyanate solution under visible light without a hole scavenger.The reaction rate constant is 2.8 times that of the photocatalyst without defect modulation.This study offers a promising strategy for developing highly efficient photocatalysts for environmental remediation.为了解决六价铬的光催化还原常常受到光催化剂中电子利用效率不高的问题,开发了一种使用硫氰酸基(—SCN)作为调节剂合成的准金属有机框架光催化剂,以增强光催化剂的电荷转移特性。—SCN引入结构缺陷,改善可见光吸收和光生电子的还原能力。—SCN显著调整电子特性,并建立稳定的电子释放路径,充当还原的活性位点。在中性硫氰酸钾溶液中,优化后的光催化剂在可见光下无需添加空穴捕获剂就能实现94.8%的Cr(Ⅵ)还原率。反应速率常数是未经缺陷化处理的光催化剂的2.8倍。这项研究提供了一种用于开发环境修复的高效光催化剂的有效策略。

关 键 词：quasi-MOF polar ligand photocatalysis hexavalent chromium reduction 

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