Facile synthesis of a mesoporous TiO2 film templated by a block copolymer for photocatalytic applications

Abstract

A facile synthesis of a mesoporous TiO₂ thin film is reported using poly(styrene-2-vinyl pyridine-ethylene oxide) polymeric micelles as a synthetic template. As the Ti precursor strongly binds with polymeric micelles in solution (before evaporation), controlled conditions, such as temperature and relative humidity, are not required for self-assembly of molecularly dissolved polymer and Ti sources. The mesoporous TiO₂ films have enhanced photocatalytic activity due to increased surface area and rough surface around the pores. Photocatalytic testing with methylene blue dye showed that the prepared mesoporous thin films were effective in degrading dyes. Degradation of methylene blue dye with nonporous TiO₂ yielded a shift in the maximum absorption wavelength, which is proposed to be the result of dimerization of methylene blue molecules during photocatalytic degradation.