Factors Affecting UV-Induced Superhydrophilic Conversion of a TiO2 Surface
Factors Affecting UV-Induced Superhydrophilic Conversion of a TiO2 Surface
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DOI：
10.1021/jp400421v
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发表时间：
2013-06-13
影响因子：
3.7
通讯作者：
Fujishima, Akira
中科院分区：
文献类型：
--
作者：
Emeline, Alexei V.;Rudakova, Aida V.;Fujishima, Akira
本研究探讨了几个因素（润湿，光强度，光谱变化的光化光，加热，和表面酸性）的亲水性转化的表面上的二氧化钛纳米涂层的影响。光致亲水表面转换的光化光的强度和波长的效率的实验依赖性清楚地表明，在亲水表面转换的电子光激发的作用。特别是，在光谱依赖性的光致亲水性转换的效率的最大极值对应于第一间接和第一直接的电子带-带跃迁在TiO 2的能量。同时，温度依赖性和表面酸性对TiO 2表面亲水行为的影响表明了多层水合物结构在表面原始亲水性和光诱导亲水转化方向中的重要性。光激发下表面能变化的估计表明，只有特定的表面位点（10（-3）-10（-4）单层）才对TiO 2表面的光致超亲水性效应负责。
The present study explored the effects of several factors (wetting, light intensity, spectral variation of the actinic light, heating, and surface acidity) on the hydrophilic conversion of the surface of TiO2 nanocoatings. The experimental dependencies of the efficiencies of photoinduced hydrophilic surface conversion on the intensity and wavelength of the actinic light clearly indicate the role of electronic photoexcitation in hydrophilic surface transformation. Particularly, the maximum extrema in spectral dependence of the efficiency of photoinduced hydrophilic conversion correspond to the energies of the first indirect and first direct electronic band-to-band transitions in TiO2. At the same time, temperature dependence and the effect of the surface acidity on the hydrophilic behavior of the TiO2 surface demonstrate the importance of the multilayer hydrate structure in both the original hydrophilicity of the surface and the direction of the photoinduced hydrophilic conversion. Estimation of the surface energy alteration under photoexcitation suggests that only specific surface sites (10(-3)-10(-4) monolayer) are responsible for the effect of photoinduced superhydrophilicity of a TiO2 surface.