Zn^(2+)掺杂二氧化钛复合薄膜的制备与性能研究

Preparation and Properties of Zn^(2+)Doped TiO_2 Composite Thin Films

本文以钛酸丁酯、二乙醇胺、硝酸锌为主要原料,在乙醇-水体系中,通过溶胶-凝胶法获得TiO2-ZnTiO3、TiO2-Zn2TiO4溶胶,经600~800℃热处理后制备了TiO2-ZnTiO3、TiO2-Zn2TiO4复合薄膜。利用XRD、SEM、AFM和接触角测试等表征方法详细研究了复合薄膜的物相、微观结构、表面形貌以及亲水性和光催化性能。结果表明:与TiO2薄膜相比,TiO2-ZnTiO3、TiO2-Zn2TiO4复合薄膜具有优越的亲水性和光催化性能。在紫外光照60 min条件下,接触角从TiO2薄膜的15.4°,下降到TiO2-Zn2TiO4复合薄膜的7.3°、TiO2-ZnTiO3复合薄膜的5.2°。在紫外光照180min条件下,亚甲基蓝降解率从TiO2薄膜的60%,提高到TiO2-Zn2TiO4复合薄膜的80%、TiO2-ZnTiO3复合薄膜的90%。由于Zn2+的掺杂增加了薄膜表面的羟基,且ZnTiO3、Zn2TiO4晶型具有催化特性,从而提高了ZnTiO3、Zn2TiO4复合薄膜的自清洁性能。

TiO2-ZnTiO3 and TiO2-Zn2ZiO4 sols were obtained with tetra-n-butyl titanate, diethanolamine and Zn （NO3 ）2 as main raw materials in ethanol-water system by sol-gel method, and the samples were calcined at 600-800 ℃ to prepare TiO2-ZnTiO3 and TiOE-ZnETiO4 composite thin films. The phase, surface morphology, hydrophilicity and photocatalytic property of the films were characterized by XRD, SEM, AFM and water contact angle apparatus. The results indicates that the hydrophilicity and photocatalytic property of TiO2-ZnTiO3 and TiO2-Zn2TiO4 composite films were more excellent than those of TiO2 films. The contact angle dropped from 15.4° for TiO2 film to 7.3° for TiO2-ZnETiO4 film and 5. 2° for TiO2-ZnTiO3 film after films were irradiated for 60 rain by UV light, and the degradation rate of methylene blue raised from 60% for TiO2 film to 80% for TiO2-Zn2TiO4 film and 90% for TiOE-ZnTiO3 film after films were irradiated for 180 min by UV light. The improvement of their self-cleaning properties can be attributed to the increase of ~ OH on the film surface due to Zn2＋ -doping and the photocatalytic property of the ZnTiO3 and ZnETiO4 crystals.