物理化学学报 >> 2012, Vol. 28 >> Issue (07): 1764-1770.doi: 10.3866/PKU.WHXB201205112

催化和表面科学 上一篇    下一篇

聚乙二醇对TiO2薄膜光致亲水性的促进作用

郑华荣, 王晓韡, 林霞晖, 耿强, 陈旬, 戴文新, 王绪绪   

  1. 福州大学光催化研究所, 福建省光催化重点实验室——国家重点实验室培育基地, 福州 350002
  • 收稿日期:2012-03-21 修回日期:2012-05-10 发布日期:2012-06-07
  • 通讯作者: 戴文新 E-mail:daiwenxin@fzu.edu.cn
  • 基金资助:

    国家自然科学基金(21073037)和国家重点基础研究发展规划项目(973) (2010CB234604)资助

Promoted Effect of Polyethylene Glycol on the Photo-Induced Hydrophilicity of TiO2 Films

ZHENG Hua-Rong, WANG Xiao-Wei, LIN Xia-Hui, GENG Qiang, CHEN Xun, DAI Wen-Xin, WANG Xu-Xu   

  1. Fujian Provincial Key Laboratory of Photocatalysis——State Key Laboratory Breeding Base, Research Institute of Photocatalysis, Fuzhou University, Fuzhou 350002, P. R. China
  • Received:2012-03-21 Revised:2012-05-10 Published:2012-06-07
  • Contact: DAI Wen-Xin E-mail:daiwenxin@fzu.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21073037) and National Key Basic Research Program of China (973) (2010CB234604).

摘要:

为了提高TiO2薄膜的光致亲水性及其持久性, 将聚乙二醇(PEG)2000 引入TiO2溶胶中, 利用提拉法在载玻片上制备出含PEG的TiO2薄膜样品, 通过测试样品紫外光照下水滴接触角的变化, 考察不同浓度PEG对TiO2薄膜光致亲水性能的影响; 并通过测试光照后的亲水薄膜样片暗处放置不同时间后接触角的变化, 比较含PEG的TiO2薄膜和纯TiO2薄膜样品的亲水持久性. 结果表明: PEG作为一种非离子型长链分子, 其适量的添加可促进TiO2薄膜的光致亲水性及其持久性. 基于薄膜样品的傅里叶变换红外(FTIR)光谱和紫外-可见漫反射光谱(UV-Vis DRS)结果, 认为PEG作为空穴捕获剂有助于TiO2薄膜中Ti3+的生成和稳定存在, 进而有助于亲水中心(表面羟基)的形成. 此研究对于TiO2光自洁涂料的应用很有意义, 也为研究TiO2的光激发瞬态行为提供了一个可能的简易方法.

关键词: 光致亲水性, 亲水持久性, 空穴捕获剂, TiO2薄膜, Ti3+物种, 聚乙二醇

Abstract:

To investigate the photo-induced hydrophilicity of TiO2 films and its durability, a series of TiO2 films containing polyethylene glycol (PEG) 2000 with different contents are prepared. The photo-induced hydrophilicity of the films is investigated by recording the water-droplet contact angle on the films? surface under UV irradiation, and the hydrophilicity durability is monitored under dark storage conditions. The photo-induced hydrophilicity of TiO2 films and its hydrophilicity durability are enhanced by introducing 2.0% (w) of PEG into the TiO2 sol. From Fourier transform infrared (FTIR) spectra and ultraviolet-visible diffuse reflection spectra (UV-Vis DRS), we infer that PEG acts as an electron donor to scavenge the photogenerated holes in TiO2 and promotes the formation of Ti3+ sites, which are induced by the Ti4+ sites accepting the photo-generated electrons of TiO2. This promotes the formation of hydrophilic sites (the surface hydroxyl species). Compared with the pure TiO2 film, the Ti3+ sites in the TiO2/PEG films are more stable, which prolongs the hydrophilicity of TiO2 films under dark conditions. This study is significant for the application of TiO2 as a self-cleaning material, and is also a facile approach to investigate the transient behaviors of TiO2 under UV irradiation.

Key words: Photo-induced hydrophilicity, Durability of hydrophilicity, Hole scavenger, TiO2 film, Ti3+ species, Polyethylene glycol

MSC2000: 

  • O643