纳米多孔TiO_2薄膜的制备与表征

以TiCl4为前躯体,两亲性三嵌段共聚物F38为模板剂,Si(100)为衬底,采用溶胶-凝胶法和旋涂涂膜工艺,制备了孔径可调的纳米多孔TiO2薄膜.研究了聚合物模板浓度与TiO2薄膜的纳米孔形态的关系.随着模板剂含量的增加,薄膜中介孔密度随之增加,约大于15%便发生介孔连通,连通后介孔成蠕虫状.同时,研究了不同的退火温度及退火方式对纳米TiO2薄膜晶相的影响.单次退火4h(600～800℃)为锐钛矿相、热稳定性好,而等时退火容易生成锐钛矿相/金红石相的混晶.

Preparation and Characterization of Mesoporous Thin Films of Titanium Dioxide

Mesoporous titania thin films with tunable pores were prepared by spin-coating precursor sols on polished Si wafers.The precursor sols were synthesized via a sol-gel method using titanium tetrachloride and amphiphilic triblock copolymer F38 as the precursor of backbone and the structure template,respectively.The dependence of the morphology of nanoporous TiO2 thin films on the mass ratio of the polymeric template was studied.The poresity of the films was found to increase with the increase of the ratio of template.With further increasing the mass ratio of F38/(F38+TiCl4) up to about 15%,the pore percolation occurred;and the mesopores were highly interconnected in a worm-like shape in a film from more polymeric template.The influence of annealing on the lattice structure of TiO2 thin film was also investigated.Upon annealing(600-800 ℃) for 4 hours,the TiO2 films were in anatase phase with good thermal stability;whereas,mixed crystallinites of anatase/rutile were found in the mesoporous TiO2 film after isochronal annealing 600 ℃.