溶胶-凝胶法制备SrTiO3:Rh及可见光水裂解制氢活性研究

摘要

Photocatalytic water splitting for hydrogen evolving is an ideal way to solve environmental and energy crisis problems. Rh doped SrTiO3 photocatalysts have been synthesized by a Sol-gel method to improve photocatalytic activity. The influence of doping amounts and prepared temperature on photo-catalytic activity was also investigated. UV-vis diffuse reflectance spectra ( DRS) showed that the Rh doping extended the absorption edge of STO to visible light region at the wavelength of 540 nm. XRD, SEM, analysis revealed that the excellent photocatalytic performance of photocatalyst prepared by a Sol-gel method was attributed to the high crystalline quality as well as smaller particle diameter( corre-sponding to relative large specific surface area). The STO:(2% Rh) calcined at 900℃ possessed the highest photocatalyitc activity for water splitting under visible light, thereby producing the average rate of H2 evolution of 289.0μmol/h ( ca. 5.9% AQY measured atλ= 420 nm) , which is higher than that of the photocatalyst prepared by a solid-state reaction ( SSR) method with 4.2% AQY.%采用溶胶-凝胶法制备了SrTiO3(STO):Rh光催化剂以提高光催化制氢活性,考察了掺杂量及合成温度对光催化活性的影响.紫外-可见漫反射(DRS)显示Rh掺杂后可以使SrTiO3的吸收达到540 nm.X射线衍射扫描电镜结果显示溶胶-凝胶法制备SrTiO3:Rh不仅具有高的结晶度而且具有较小的粒径(对应于大的比表面积)从而具有较高的活性.当Rh的负载量为2%(质量分数),焙烧温度为900℃,光催化材料具有最高的活性,产氢速率为289.0μmol/h,420 nm的量子效率为5.9%,高于固相法制备的材料的产氢活性(AQY=4.1%).