单斜晶型钒酸铋空心纳米球的制备及其光催化性能

Synthesis of hollow BiVO_4 Nanospheres with Monoclinic Scheelite Structure and their Photocatalytic Property

无需添加任何模板剂,以Bi(NO3)·5H2O和NH4VO3为原料,采用柠檬酸络合法结合热处理的方法成功合成了BiVO4空心纳米球.采用TEM、XRD、TG-DTA、UV-Vis等测试手段对样品的形貌、相结构、光吸收性能进行了表征,以亚甲基蓝染料溶液的脱色降解实验为模型反应考察了样品的光催化性能.结果表明,所制备的BiVO4以单斜晶系白钨矿相存在且具有良好的中空结构,空心球平均粒径为160 nm,空腔直径为10～80 nm.UV-Vis谱图数据表明所制备的BiVO4样品的禁带宽度约为2.26 eV,样品在紫外区和可见区均有较强的光吸收.可见光照射下,亚甲基蓝溶液经BiVO4空心球脱色处理150 min后,脱色率可达到95%以上,COD去除率为73.66%.另外,考察了柠檬酸与铋离子不同摩尔比对空心球形貌的影响,并对BiVO空心纳米球的形成机理进行了探讨.

Without any template,bismuth vanadate（BiVO4） samples were successfully synthesized using Bi（NO3）·5H2O and NH4VO3 as reactants.TEM,X-ray diffraction,TG-DTA and UV-Vis diffusion reflectance were employed to characterize the morphology,surface structure,and optical absorption properties of the hollow BiVO4 nanospheres.The decolorizng performance of hollow BiVO4 nanospheres on methylene blue waste water was investigated.Results showed that BiVO4 nanospheres possessed monoclinic structure,the diameter of this hollow sphere was about 160 nm and the pore diameter was 10～80 nm.The photo-absorption property showed that the band gap of the sample was ca.2.26 eV,and the hollow BiVO4 nanospheres had strong photo-absorption property in both UV and visible regions.The decolorizing efficiency for methylene blue can reach to 95% or more,and mineralizing efficiency was 73.66 %.In addition,the different molar ratio of HLc and Bi3＋ had an important effect on the morphology of BiVO4.Based on this result,the formation mechanism of hollow BiVO4 nanospheres was discussed preliminarily.