微乳液法合成新型可见光催化剂BiVO4及光催化性能研究

以Bi(NO₃)₃、NH₄VO₃为原料，采用微乳液法合成了新型可见光活性的钒酸铋（BiVO₄）光催化剂，并利用XRD、SEM、XPS、BET等技术手段对其进行了表征. 以可见光(λ>400nm)为光源，以甲基橙的光催化降解为模型反应，考察了BiVO₄ 的可见光催化性能. 结果表明：采用微乳液法通过调节合成温度，可得到不同晶相的BiVO₄光催化剂. 四方相BiVO₄在低温下首先生成，随温度升高四方相开始向单斜相转变. 可见光催化实验结果表明，四方相和单斜相共混的BiVO₄的光催化效率最高，3h内使甲基橙的脱色率达到99.9%.

Synthesis of Novel Visible Light Driven BiVO4 Photocatalysts via Microemulsion Process and its Photocatalytic Performance

The novel visible light driven BiVO₄ photocatalyst with tetragonal and monoclinic structures was synthesized via a reverse microemulsion method using Bi(NO₃)₃ and NH₄VO₃ as starting materials. The as prepared BiVO₄ samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X ray photoelectron spectroscope (XPS). The photocatalytic activity of the BiVO₄ powders was determined by degradation of methyl orange molecules in water under visible light irradiation (λ>400nm). The results revealed that the particle and crystallite sizes of the BiVO₄ powders significantly depended on synthesis temperature of the reverse microemulsion solutions. The photocatalytic tests indicated that the synthesis temperature of the microemulsion solutions can significantly affect the visible light driven photocatalytic activities. The highest methyl orange degradation of 99.9% within 3h was achieved on the BiVO₄ samples with mixed tetragonal and monoclinic phases.