Synthesis of TiO2 porous thin films by polyethylene glycol templating and chemistry of the process

Titanium dioxide porous films have been deposited on glass slides by sol-gel technology. Tetrabutylorthotitanate and polyethylene glycol were used as a precursor and template, respectively. The chemical mechanism is discussed in relation to the sol-gel transition, which provides a possible theoretic explanation to the formation of TiO2 porous films. The morphology of porous TiO2 thin films strongly depends on the amount of water, the types of solvents and complexing agents, and the concentration and molecular weight of the template. It was shown that the diameter of pores is tunable in the range of 10-500 nm and the maximum of BET specific area of the films is 72 m(2)/g. (c) 2004 Elsevier Ltd. All rights reserved.