用酸催化溶胶－凝胶技术合成了硫掺杂纳米TiO2光催化剂粉末. 光催化降解亚甲基蓝实验结果表明, 当硫脲与钛酸丁酯摩尔比S/Ti为3.5时, 经500℃热处理后的催化剂的光催化活性最佳. 通过XRD、DRS和XPS等研究表明硫掺杂导致二氧化钛晶粒尺寸细化, 并有效抑制了相变温度. 在热处理过程中硫由S2-被氧化为S4+并进入到二氧化钛的晶格中取代了部分Ti4+位, 导致了晶格的畸变, 带隙变窄, 从而导致对光的吸收发生了向可见光区移动.
S-doped TiO2 nanopowders were prepared by a sol-gel method with acid as the catalyst. The results of photocatalytic degradation methylene blue demonstrated that the doped TiO2 exhibited the highest photocatalytic activity when the mole ratio of thiourea and tetrabutyltitanate[Ti(OC4H9)4] was 3.5 and the doped TiO2 was calcined at 500℃ for 2h. The results from the X-ray diffraction (XRD), diffusion reflectance spectra (DRS) and X ray photoelectron spectroscopy (XPS) showed that sulfur doping controlled the increasing of nano TiO2 and restrained
the transformation from anatase to rutile. S2- was oxidezed to S4+ during
the thermal treatment. The trance of sulfur ions (S4+) substitued partially
for the lattice titanium ions (Ti4+), which resulted in the localized crystal
deformation of TiO2 and the bandgap between valence band and conduction
band narrowed, and the absorption light transferred to visible light region.
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