Low-Temperature Synthesis of Nanometer-Sized Crystalline TiO2 Particles and Their Photoinduced Decomposition of Formic Acid

Abstract

Anatase TiO2 particles with an average size of 2.7 nm in an as-grown state were obtained below 373 K from an H2O–EtOH mixed solution of TiOSO4 by a facile liquid phase method. The volume ratio of H2O to EtOH was revealed to be the key for crystallinity of the particles. The as-grown particles prepared from the H2O–EtOH solution (H2O/EtOH (mL/mL) = 150/100) showed a high photoreactivity in the TiO2 photoinduced decarboxylation of HCOOH under a deaerated condition. In contrast, under an aerated condition, the rate of the reaction increased with an increase in calcining temperature (Tc) due to the improvement of anatase crystallinity, going through a maximum at Tc = 873 K.