Effect of compressive stress inducing a band gap narrowing on the photoinduced activities of sol-gel TiO2 films
Effect of compressive stress inducing a band gap narrowing on the photoinduced activities of sol-gel TiO2 films
复制标题
DOI：
10.1016/j.tsf.2011.08.097
复制
发表时间：
2011-11-30
期刊：
影响因子：
2.1
通讯作者：
Robert, D.
中科院分区：
文献类型：
--
作者：
Ghazzal, Mohamed N.;Chaoui, N.;Robert, D.
采用溶胶-凝胶法制备了在不同基质上生长的TiO2薄膜。x射线衍射显示，TiO2晶格参数c连续减小，表明压应力连续变化，在钠钙玻璃（SLG）上生长的薄膜的压应力可以忽略，在硼硅玻璃（BSG）上生长的薄膜的压应力中等，在石英衬底（QS）上沉积的薄膜的压应力较大。紫外可见吸收光谱显示TiO2薄膜的吸光度边缘出现红移，表明带隙减小，这是压应力增大的直接结果。x射线光电子能谱分析表明，除了钠离子浓度不同外，氧化钛膜的表面组成基本相似。硬脂酸在TiO2/QS上的光氧化速率是TiO2/BSG的2倍，是TiO2/SLG的1000倍左右。光致润湿性与压应力有相同的依赖关系。根据这些结果，可以利用压缩应力来调节氧化钛的带隙，以提高其光致性能。(C) 2011 Elsevier B.V.版权所有
TiO2 thin films grown on different kinds of substrates were obtained by sol-gel process. X-ray diffraction revealed that the TiO2 lattice parameter c decreased continuously, indicating a continuous variation in the compressive stress, a negligible compressive stress of the film grown onto Soda-Lime Glass (SLG), medium compressive stress of the film grown onto BoroSilicate Glass (BSG) and large compressive stress of the film deposited onto the Quartz Substrate (QS). UV-Vis absorbance spectra exhibited a red-shift of the absorbance edge of the TiO2 films suggesting a lowering of the band gap, which is a direct consequence of the increase of the compressive stress. X-ray photoelectron spectroscopy revealed that the surface composition of titania films was similar except for sodium-ion concentration. The rate observed during the photo-oxydation of the stearic acid on TiO2/QS was twice as high as that of TiO2/BSG and about 1000 times superior to that of TiO2/SLG. The photoinduced wettability shows an identical dependence of the compressive stress. According to these results, the compressive stress could be used to tune the band gap of the titanium oxide in order to enhance the photoinduced properties. (C) 2011 Elsevier B.V. All rights reserved.