采用溶胶-凝胶法制备了钛酸锶, 进而用固相法制备了氮掺杂SrTiO3, 并用光沉积和氢气还原法制备了Pt负载的氮掺杂SrTiO3光催化剂. 用XRD、SEM、UV-Vis漫反射和荧光光谱对其进行了表征和分析, 考察了光催化剂在可见光下的产氢活性. 研究了不同氮源、掺杂量、烧结温度和Pt负载量对催化剂产氢活性的影响. 结果表明, 三种不同氮源剂其掺杂效果为六次亚甲基四胺(HMT)>EDTA>尿素, 而EDTA掺氮效果稍低于HMT. 当氮源剂为HMT, SrTiO3与HMT质量比为1:3, 焙烧温度为450℃时, 所制备的光催化剂具有最佳的光催化产氢活性. 在负载金
属铂后, 产氢活性有较大幅度的提高, 其中用氢气还原法制备所得的光催化剂较光沉积法制备的具有更高的光催化活性, 在最佳负载量均为2wt％时, 两种光催化剂6h内的产氢量分别为6.89mmol和2.24mmol, 分别是未负载铂样品产氢量的12倍和4倍多.
SrTiO3 photocatalysts were prepared by a sol-gel method, and nitrogen-doped SrTiO3 were further prepared by a solid phase method. Nitrogen-doped SrTiO3 loaded with Pt were prepared by photodeposition method and hydrogen reduction method. These photocatalysts were characterized by XRD, SEM, UV-Vis diffuse reflectance spectra, fluorescence spectrum and the photocatalytic hydrogen generation activities were investigated under visible light irradiation. The effects of different nitrogen sources, doped content, calcination temperature and the content of loaded Pt on the hydrogen generation activity of catalysts were investigated. The results indicate that three nitrogen source reagents demonstrate different doping effect, i.e. hexamethylenetetramine(HMT)>EDTA>urea and the doping effect of EDTA is slightly lower than HMT. On the condition that the nitrogen source is HMT, the mass proportion of SrTiO3 and HMT is 1:3, and the calcination temperature is 450℃, the optimized photocatalytic hydrogen generation activity of photocatalysts can be achieved. The photocatalytic hydrogen generation activity is greatly improved by loading metal Pt. The photocatalytic activity of photocatalysts prepared by hydrogen reduction method is better than that prepared by photodeposition method. On the condition that the optimized loaded content is 2wt％, the hydrogen generation amounts of these two photocatalysts are up to 6.89mmol and 2.24mmol within 6h respectively, which are 12 times and 4 times more than that of the unloaded Pt samples.
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