Photocatalytic and Photoelectrochemical Characteristics of Mesoporous Titanium Dioxide Microspheres

Abstract

It was established that the mesoporous microspheres with size of about 10 nm formed by anatase nanocrystals exhibit photocatalytic activity in the release of H 2 from water-ethanol mixtures and in the gas-phase oxidation of benzene by atmospheric oxygen. They are also active during the generation of current in a photoelectrochemical cell exposed to UV light or in TiO 2 /CdS heterostructures exposed to visible light. It was shown that the efficiency of the photoprocesses involving the mesoporous microspheres significantly exceeds that of nonporous nanocrystalline Evonik P25 TiO 2 . Possible reasons for the enhanced photoactivity of the microspheres are discussed.

Synthesis and characterization of different binary and ternary phase mixtures of mesoporous nanocrystalline titanium dioxide

“…It should be emphasized that anatase is the only crystalline phase (in the absence of signs of phase transformation) of mesonc-TiO 2 formed under neutral conditions. Almost all the obtained samples are highly effective photocatalysts for water reduction, gas-phase oxidation of alcohol and benzene [61][62][63][64].…”

“…Earlier, under conditions of neutral hydrolysis, samples of thermally stable meso-nc-TiO 2 with a pure anatase structure were obtained [59][60][61][62][63], demonstrating different textures with well-defined spherical morphology (microand nanospheres) and a narrow pore distribution. Calcined at 500 °C after hydrothermal treatment at 175 °C TiO 2 samples had a radically more developed porous structure compared to samples without hydrothermal treatment [59].…”