Jeon Harim, Lee Chang Soo, Patel Rajkumar, Kim Jong Hak
†Department of Chemical and Biomolecular Engineering, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, South Korea.
ACS Appl Mater Interfaces. 2015 Apr 15;7(14):7767-75. doi: 10.1021/acsami.5b01010. Epub 2015 Apr 2.
We report the facile synthesis of a well-organized meso-macroporous TiO2/SiO2 thin film with high porosity and good interconnectivity from a binary mixture (i.e., titania precursor and polymer template). Our process is based on self-assembly of the amphiphilic rubbery comb copolymer, poly(dimethylsiloxane)-g-poly(oxyethylene methacrylate) (PDMS-g-POEM) with titanium tetraisopropoxide (TTIP). SiO2 is self-provided by thermal oxidation of PDMS chains during calcination under air. The selective, preferential interaction between TTIP and the hydrophilic POEM chains was responsible for the formation of well-organized TiO2/SiO2 films, as supported by transmission electron microscopy, scanning electron microscopy, X-ray photospectroscopy, and X-ray diffraction analyses. We investigated in detail the effect of precursor content, solvent type, and polymer concentration on thin film morphology. Photodegradation of methyl orange by the well-organized meso-macroporous TiO2/SiO2 film was greater than that of a dense TiO2 film prepared without PDMS-g-POEM as well as a SiO2-etched TiO2 film. These results indicate that the well-organized structure and SiO2 doping of the TiO2 film play a pivotal role in enhancing its photocatalytic properties.
我们报道了一种简便的合成方法，可从二元混合物（即二氧化钛前驱体和聚合物模板）制备出具有高孔隙率和良好互连性的有序介观大孔TiO₂/SiO₂薄膜。我们的方法基于两亲性橡胶梳状共聚物聚（二甲基硅氧烷）-g-聚（甲基丙烯酸氧乙烯酯）（PDMS-g-POEM）与四异丙醇钛（TTIP）的自组装。在空气中煅烧期间，PDMS链的热氧化可自行提供SiO₂。透射电子显微镜、扫描电子显微镜、X射线光电子能谱和X射线衍射分析表明，TTIP与亲水性POEM链之间的选择性优先相互作用导致了有序TiO₂/SiO₂薄膜的形成。我们详细研究了前驱体含量、溶剂类型和聚合物浓度对薄膜形态的影响。有序介观大孔TiO₂/SiO₂薄膜对甲基橙的光降解作用大于未使用PDMS-g-POEM制备的致密TiO₂薄膜以及经SiO₂蚀刻的TiO₂薄膜。这些结果表明，TiO₂薄膜的有序结构和SiO₂掺杂在增强其光催化性能方面起着关键作用。
