WO_3/TiO_2光催化剂的制备及光催化产氢性能研究

Preparation and photocatalytic H_2-production performance of WO_3/TiO_2 photocatalyst

针对催化剂TiO_2禁带宽度较宽、光响应范围较窄的问题,对TiO_2进行改性,采用溶胶凝胶法制备了不同复合比例的WO_3/TiO_2催化剂以提高TiO_2的光催化活性。应用SEM,BET,XRD,UV-Vis,FT-IR等方法对催化剂进行表征,分析了不同复合比对WO_3/TiO_2样品形貌、晶型、比表面积和产氢速率的影响。当入射波长为300~600 nm,2%WO_3/TiO_2的吸光度大于TiO_2的吸光度,吸收带边红移。通过300 W氙灯照射进行光解水制氢的测试,评价了不同WO_3/TiO_2样品的光催化分解水产氢活性。结果表明:复合比为2%时,WO_3/TiO_2的光解水产氢活性最佳,最高可达14 445.3μmol/(h·g),其产氢速率是TiO_2的10倍,同时探讨分析了光催化反应机理。这将在太阳能光解水产氢领域有着广泛的应用前景。

In order to enhance the photocatalytic activity of TiO2 which has a wide band gap width but a narrow range in light responsive region, a series of WO3/TiO2 composite photocatalysts with different composite proportions were prepared by a sol-gel method.The prepared samples were characterized by Scanning Electron Microscopy, N2 physical adsorption, X-ray diffraction, UV-visible spectroscopy and Fourier transform infrared spectroscopy.The effects of different composite proportions on the morphology, crystal structure, specific surface area and photocatalytic activity of WO3/TiO2 were investigated.The photocatalytic activity of the samples was evaluated by photo-catalysis water splitting under 300W Xenon lamp.In addition, the reaction mechanism over the composite catalyst was discussed.The results showed that, when λ was 300 to 600 nm, the absorbance of 2%-WO3/TiO2 was greater than the absorbance of TiO2, the absorption band edge was redshifted.As the composite ratio was 2%, the hydrogen photolysis aquatic activity of WO3/TiO2 was the best, with a highest value of 14445.3 μmol/（h·g）, concentration of WO3 showed 10 times photocatalytic activity compared to pure TiO2.The photocatalyst technology would have extensive applications in the field of water splitting by solar light.