球形Bi_2WO_6光催化剂的合成与性能

Synthesis and photocatalytic properties of spherical Bi_2WO_6 photocatalysts

以Bi(NO)3·5H2O、Na2WO4·2H2O为原料,采用水热合成法成功制备出纳米片组成的球形Bi2WO6,并采用X射线衍射(XRD)、扫描电子显微镜(SEM)和紫外-可见漫反射(UV-Vis)技术对其进行分析表征,研究水热温度和反应时间对催化剂合成的影响。通过在紫外及可见光(λ>420 nm)照射下,降解罗丹明B(RhB、5 mg/L)溶液来评估其光催化活性,并且考察了催化剂投加量、RhB的初始浓度、光源对罗丹明B降解率的影响。结果表明,在180℃水热7 h为最佳制备工艺;催化剂的投加量为2 g/L时,以紫外光为光源,照射120 min对RhB的降解率可达到99.8%。

Spherical Bi2WO6 photocatalysts were synthesized by hydrothermal method with different hydrothermal temperature and reaction time using Bi（NO）3？5H2O and Na2WO4？2H2O as raw materials, which were further characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and UV-Vis diffusion reflectance spectra techniques. The photocatalytic activity of Bi2WO6 photocatalysts was evaluated by degrading Rhodamine B （RhB, 5 mg/L） under ultraviolet and visible light irradiation （λ＆gt;420 nm）. The influence of dosage of catalyst, initial concentration of RhB and light source on degradation rate was also investigated. The results indicate that 180 ℃ and 7 h are the proper conditions for preparing Bi2WO6 powders. When the dosage of Bi2WO6 catalyst is 2 g/L and the ultraviolet irradiate time is 120 min, the degradation rate of RhB is up to 99.8%.