双负载策略构建Au-BiOBr-TiO2光催化剂在可见光下快速高效降解黄药
Dual-loading strategy to construct Au-BiOBr-TiO2 photocatalysts for fast and efficient degradation of xanthates under visible light
戚耀中 1沈岩柏 1赵思凯 1蒋潇宇 1高淑玲 1韩聪 1刘文宝 1伞晓广 2孟丹2
作者信息
- 1. School of Resources and Civil Engineering,Northeastern University,Shenyang 110819,China
- 2. College of Chemical Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China
- 折叠
摘要
浮选废水中残留的黄药会严重影响矿区周围生态环境.为了实现对黄药的高效降解,通过水热法、水浴沉淀法和光沉积法制备的Au-BiOBr-TiO2(AuBT)三元复合光催化剂对废水进行处理是一种有效手段.在模拟降解矿物浮选废水实验中,AuBT表现出卓越的光催化降解性能.实验结果表明,0.2 g/L的AUBT光催化剂在20 min可见光照射下对初始浓度为20 mg/L黄药的光催化去除率可达到95.20%.机理检测表明,AuBT有效降低了带隙并扩大光响应范围,提高了材料的光催化活性.DFT计算表明部分电子向乙基黄药(SEX)分子转移,而这有助于激发光催化过程.自由基清除实验表明反应体系中的主要活性物种是光生空穴(h+),其次是超氧自由基(·O-2).作为高效的光催化剂,AuBT在可见光下可降解各种类型的黄药,在浮选废水处理环节体现了巨大的潜力.
Abstract
With the advancement of mining operations,xanthate as an essential flotation reagent is unavoidably released into natural water bodies through flotation effluent.To protect the surrounding environment of mines,Au-BiOBr-TiO2(AuBT)ternary composites were constructed and utilized as an optimal photocatalyst in the degradation process of xanthates.AuBT with high purity was prepared by the integrated techniques of hydrothermal,water bath precipitation,and photodeposition.BiOBr nanosheets and Au nanoparticles were uniformly distributed on the surface of TiO2 particles in the composites.In simulated mineral flotation effluents,AuBT showed excellent degradation performance in the catalytic oxidation of 20 mg/L xanthate under visible light irradiation,achieving 95.2%removal rate in 20 min.The experiments and characterization results revealed that the dual-loading strategy to construct AuBT photocatalysts effectively decreased the band gap and broadened the photoresponse range of pristine TiO2,which was significant for the improvement of the photocatalytic activity.DFT calculations demonstrated that partial electrons were transferred around the sodium ethyl xanthate(SEX)molecule and the accumulated charge contributed to the oxidation process.Experimental results of free radical scavenging indicate that the main active species in the reaction system are photogenerated holes(h+),followed by superoxide radicals(·O-2).This work indicates that AuBT composites can be used as an efficient photocatalyst to completely degrade various types of xanthates under visible light,which exhibits great potential in flotation wastewater treatment.
关键词
Au-BiOBr-TiO2/三元复合材料/光催化/可见光/黄药Key words
Au-BiOBr-TiO2/ternary composites/photocatalysis/visible light/xanthates引用本文复制引用
基金项目
国家自然科学基金(52274255)
国家自然科学基金(51674067)
国家重点研发计划(2020YFB2008702)
中央高校基本科研业务费专项(N2201008)
中央高校基本科研业务费专项(N2201004)
Liaoning Revitalization Talents Program,China(XLYC1807160)
中国博士后科学基金(2022M720025)
Postdoctoral Foundation of Northeastern University,China()
Young Elite Scientists Sponsorship Program by CAST,China(2022QNRC001)
出版年
2023
NETL
NSTL
万方数据