Hydrogen evolution from aqueous methanol solution on mesoporous titania prepared by a process combining evaporation induced self-assembly and spray pyrolysis

Abstract

Mesoporous TiO2 powders were prepared in 1 min from an aqueous mixture of chelated complex titanium precursor and tri-block copolymer by using a process combining evaporation induced self-assembly (EISA) and spray pyrolysis. Photocatalytic activity was evaluated by measuring the rate of hydrogen evolution from methanol solution. The prepared powders were mainly anatase phase and had worm-like pores. Crystallite size was in the range from 7.8 to 18.6 nm in diameter. The mesoporous TiO2 powders calcined at 823 K had surface area of 144 m(2) g(-1) and high pore volume of 0.33 cm(3) g(-1). Pore size distribution was also narrow. In addition, it had high light absorption intensity below 350 nm. The rate of hydrogen evolution was by a factor of six higher than the rate measured with commercial nano-sized TiO2 powder (Degussa P-25). Unique structural and optical properties, which were mainly originated from our new combined process of EISA and spray pyrolysis, contributed to the enhanced rate of hydrogen evolution. (C) 2012 Elsevier B.V. All rights reserved.