分别在导电铝合金片(Al)和具有阳极氧化铝层的非导电铝片(AAO/Al),以及铟锡氧化物导电玻璃(ITO/glass)和普通非导电玻璃(glass)表面通过提拉法制备出TiO2/Al和TiO2/AAO/Al,以及TiO2/ITO/glass和TiO2/glass两组TiO2薄膜样品,通过测试紫外光照下水滴接触角的变化考察TiO2薄膜的光致亲水性.结果表明,相对于TiO2/Al2O3/Al,基底导电的TiO2/Al表现出较好的光致亲水性能;而相对于TiO2/glass,基底导电的TiO2/ITO/glass表现出较差的光致亲水性能.分析认为,Al和ITO两导电基底和TiO2薄膜间的不同电子转移方向影响TiO2薄膜的光致亲水性能,Al片提供电子给TiO2有助于提高以光生电子为主要初级活性物种的光致亲水性,而ITO接受TiO2的光生电子,导致光致亲水性的下降.
TiO2 films on Al alloy(Al),anodic aluminum oxide(AAO/Al,formed at the surface of Al alloy),indium-tin oxide glass(ITO/glass) and glass were prepared by a dip coating method.The measurement of water drop contact angle under UV irradiation shows that TiO2 films on the conducting Al substrate have a higher activity for photoinduced hydrophilicity than that on the non-conducting AAO/Al substrate.Alternatively,TiO2 films on the conducting ITO/glass substrate have a lower activity for photoinduced hydrophilicity compared to TiO2 films on the non-conducting substrate glass.These observations are due to electron transfer between TiO2 and substrates.Al acts as an electron donor and donates electrons to TiO2,which results in an increase in the photoinduced hydrophilicity of TiO2 film.ITO accepts the photogenerated electrons,which results in a decrease in the photoinduced hydrophilicity of TiO2 films.