摘要
卤氧化铋由于具有特殊的层状结构和合适的禁带宽度,表现出良好的可见光催化活性和稳定性。改变卤氧化铋复合物中卤素的组成能调节禁带宽度,优化光催化性能。采用溶剂热法制备了纳米片层状BiOBr_xI_(1-x)固溶体催化剂,利用XRD、SEM和紫外-可见漫反射谱分析了BiOBr_xI_(1-x)固溶体催化剂的结构、形貌和光学特性,并以甲基橙为目标降解物,评价其可见光催化活性。结果表明:与单体卤氧化铋相比,BiOBr_xI_(1-x)固溶体催化剂提高了可见光激发率和载流子转移率,对甲基橙的降解效果更好;当Br/I比为4/6时,BiOBr_xI_(1-x)固溶体催化剂的光催化活性最高,其降解速率常数是组成为40% BiOBr+60% BiOI的机械混合催化剂的2.7倍。通过添加活性组分捕获剂研究其光催化降解机理的结果显示:BiOBr_xI_(1-x)固溶体催化剂光降解甲基橙过程中h^+直接氧化甲基橙分子起主导作用,也存在一定的·O_2^-对甲基橙的氧化作用。
Bismuth oxide halides exhibit good photocatalytic activity and stability due to their special layered structure and suitable band gap.Changing the composition in bismuth oxide halides can adjust the band gap and optimize the photocatalytic performance.By using solvothermal method,this paper prepares nanosheet-like BiOBr x I 1-x solid solution catalysts,and characterizes the structure,morphology and optical properties of the prepared catalysts by XRD,SEM and UV-vis diffuse reflectance spectrum.Then the paper evaluates the photocatalytic activity of the catalysts by using methyl orange as the target of degradation,and explores the photocatalytic degradation mechanism of the catalysts by adding the trapping agents of active component.The results show that the solid solution catalyst has higher visible light excitation,carrier transfer rate and better photocatalytic activity than pure BiOBr or BiOI catalyst.When the Br/I ratio is 4/6,the photocatalytic activity is the highest,and the degradation rate constant is 2.7 times of the mechanical mixture catalyst of 40%BiOBr+60%BiOI.The direct oxidation of methyl orange by h^+plays a dominant role,and the oxidation of methyl orange by·O2^-exists.
作者
洪建和
何家宁
胡鹏
何岗
沈翔
HONG Jianhe;HE Jianing;HU Peng;HE Gang;SHEN Xiang(Faculty of Materials Science and Chemistry,China University of Geosciences (Wuhan),Wuhan 430074,China)
出处
《安全与环境工程》
CAS
北大核心
2019年第1期1-6,共6页
Safety and Environmental Engineering
基金
国家重点研发计划政府间专项项目(2016YFE0119600)
关键词
纳米片层状BiOBrxI1-x
甲基橙
光催化活性
光催化降解机理
溴氧化铋
碘氧化铋
溶剂热法
nanosheet-like BiOBrxI1-x
methyl orange
photocatalytic activity
photocatalytic degradation mechanism
bismuth oxybromide
bismuth oxyiodide
solvothermal method
