WO_3/Bi_(12)SiO_(20)光催化降解气相苯

用气液反应法和化学溶液分解技术(CSD)分别制备了WO3和Bi12SiO20粉末,并将二者耦合,合成出WO3/Bi12SiO20复合光催化剂.以气相苯的降解为探针反应,考查了催化剂的光催化活性.结果表明:耦合后的WO3/Bi12SiO20催化剂的催化活性显著提高,其中30%(w)WO3/Bi12SiO20在紫外光下对苯的降解率明显优于P-25,而且催化剂具有一定的可见光响应能力.采用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、N2吸附-脱附(BET)和紫外-可见漫反射(UV-VisDRS)等手段对催化剂进行了表征.结果表明:WO3与Bi12SiO20之间存在良好的能带协同作用.WO3与Bi12SiO20耦合后,催化剂的光响应范围拓宽,光生电子和空穴能有效地分离,光生电子和空穴产生速率增大,所以催化剂活性提高.

Photocatalytic Degradation of Gas Phase Benzene over WO2/Bi12SiO20

WO₃ and Bi₁₂SiO₂₀ powders were prepared by a gas-liquid reaction and chemical solution decomposition, respectively. WO₃/Bi₁₂SiO₂₀ photocatalysts were coupled by mixing WO₃ and Bi₁₂SiO₂₀. The reduction of benzene was used to investigate the activity of WO₃/Bi₁₂SiO₂₀. The results indicate that the activity of the coupled WO₃/Bi₁₂SiO₂₀ catalysts increased substantially. The degradation behavior of benzene over 30%(w) WO₃/Bi₁₂SiO₂₀ under UV irradiation was obviously better than that of P-25, and the degradation of benzene under visible light was also considerable. The photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The results showed that there was a good synergistic effect between WO₃ and Bi₁₂SiO₂₀. The photogenerated electrons and holes were effectively separated after coupling between WO₃ and Bi₁₂SiO₂₀ and the rate of electron and hole production increased. The electrons and holes were effectively separated and the photocatalytic activity increased accordingly.