催化学报 ›› 2012, Vol. 33 ›› Issue (12): 1982-1987.DOI: 10.3724/SP.J.1088.2012.20901

• 研究论文 • 上一篇    

BiVO4 颗粒的聚丙烯酰胺凝胶法制备及光催化性能和机理

孙军辉2, 杨华1,2,*, 县涛1,2, 王伟鹏2, 冯旺军2   

  1. 1兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室, 甘肃兰州 730050; 2兰州理工大学理学院, 甘肃兰州 730050
  • 收稿日期:2012-09-05 修回日期:2012-10-22 出版日期:2013-01-18 发布日期:2012-12-18

Polyacrylamide Gel Preparation, Photocatalytic Properties, and Mechanism of BiVO4 Particles

SUN Junhui2, YANG Hua1,2,*, XIAN Tao1,2, WANG Weipeng2, FENG Wangjun2   

  1. 1State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050, Gansu, China; 2School of Science, Lanzhou University of Technology, Lanzhou 730050, Gansu, China
  • Received:2012-09-05 Revised:2012-10-22 Online:2013-01-18 Published:2012-12-18

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 400 nm, 带隙为 2.49 eV. 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.

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

Abstract: BiVO4 particles were prepared by a polyacrylamide gel method and characterized by X-ray diffraction, scanning electron microscopy, 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.

Key words: bismuth vanadate, nanoparticle, polyacrylamide gel method, photocatalytic mechanism, hole, hydroxyl radical