乙二胺四乙酸辅助水热法制备钼酸铋及其可见光催化活性

Ethylenediamine Tetraacetic Acid-Assisted Hydrothermal Synthesis of Bismush Molybdate and Its Photocatalytic Activity Under Visible Light Irradiation

以Bi(NO3)3·5H2O和(NH4)6Mo7O24·4H2O为原料、乙二胺四乙酸(ethylenediamine tetraacetic acid,EDTA)为络合剂,辅助水热法成功合成了Bi2MoO6光催化剂。采用X射线粉末衍射仪、扫描电子显微镜、场发射高分辨透射电镜、红外光谱仪、Raman光谱仪、紫外-漫反射光谱仪对产品Bi2MoO6进行了表征和分析。结果表明:添加1.0g EDTA辅助水热法能够合成出结晶良好斜方晶系的匕首形状的Bi2MoO6光催化剂,该样品的紫外-可见光吸收边发生了稍许红移,其能带隙减小至2.54eV;可见光照射120min后,对初始浓度为10-5 mol/L的罗丹明B溶液的脱色率就可达到100%未添加EDTA的Bi2MoO6样品,光降解180min后的脱色率仅达到62.75%。同时,对Bi2MoO6样品光催化活性提高的机理进行了分析。

Bi2 MoO6 photocatalyst was synthesized by a hydrothermal method with Bi（ NO3 ） 3 -5 H20 and （ NH4 ） 6 MoT O24 - 4 H20 as raw materials and ethylenediamine tetraacetic acid （EDTA） as a chelating agent. The samples were characterized by X-ray diffraction, scanning electron microscopy, field emission high resolution transmission electron microscopy, infrared spectrosco- py, Raman spectoscopy and UV-Vis diffusion reflectance spectroscopy, respectively. The results show that the highly crystal- linity dagger-like Bi2 MoO6 with an orthorhombic structure can be obtained via the EDTA-assisted hydrothermal route. Com- pared to Bi2 MoO6 samples without EDTA, the absorption band of the samples assisted with EDTA of 1.0 g appears a little red shift, and its band gap is 2.54eV. A higher photocatalytic activity of the Bi2MoOx samples with EDTA of 1.0 g occurs under visible light irradiation, and the decolorization rate of Rhodamine B of 10-5 tool. L 1 solution is 100 % after visible light irradia- tion for 120rain. However, the decolorization rate of the Bi2MoO6 samples without EDTA is only 62.75% after visible light ir- radiation for 180min. In addition, the mechanism of enhanced photocatalytic activity was also discussed.