摘要
采用聚丙烯酰胺凝胶法制备了BiVO4颗粒,利用X射线衍射、扫描电镜和紫外-可见漫反射光谱对样品进行了表征.结果表明,所制BiVO4颗粒为单斜白钨矿结构,其形貌规整,近似呈球形,颗粒尺寸分布均匀,平均粒径约为400nm,带隙为2.49eV.以亚甲基蓝为目标降解物,在模拟太阳光辐照下考察了BiVO4颗粒的光催化性能,研究了O2,N2,乙醇及KI的添加对光催化效率的影响.以对苯二甲酸为探测剂,采用荧光光谱检测了催化剂在模拟太阳光照射下产生羟基自由基(·OH)的情况,探讨了其中的光催化机理.研究表明,?OH和光生h+是BiVO4光催化降解亚甲基蓝的两种主要活性物种.
BiVO4 particles were prepared by a polyacrylamide gel method and characterized by X-ray diffraction, scanning electron micros- copy, and ultraviolet-visible diffuse reflectance spectroscopy.The results demonstrate that the as-prepared BiVO4 particles crystallize in a monoclinic scheelite-type structure, are regularly shaped like spheres with a uniform size of ～400 nm, and have a bandgap energy of 2.49 eV. The photocatalytic activity of BiVO4 particles was evaluated by the degradation of methylene blue under simulated sunlight irradiation. The effects of O2, N2, ethanol, and KI on the photocatalytic efficiency were investigated. Hydroxyl radicals （·OH） formed on the catalyst under simulated sunlight irradiation were detected by photoluminescence spectroscopy using terephthalic acid as a probe molecule. The photocatalytic degradation mechanism involved is discussed in detail. Based on the photocatalytic results, hydroxyl radicals and photogenerated h＋ are suggested to be the two main active species toward the photocatalytic degradation of methylene blue by BiVO4.
出处
《催化学报》
SCIE
EI
CAS
CSCD
北大核心
2012年第12期1982-1987,共6页
基金
国家自然科学基金(50962009
51262018)
甘肃省自然科学基金(1010RJZA041)
兰州理工大学优秀青年基金(Q200902)~~
关键词
钒酸铋
纳米颗粒
聚丙烯酰胺凝胶法
光催化机理
空穴
羟基自由基
bismuth vanadate
nanoparticle
polyacrylamide gel method
photocatalytic mechanism
hole
hydroxyl radical
