Synthesis of [111]-/{101} facets co-exposed anatase TiO2 nanocrystals with improved photocatalytic performance

Abstract:

Cuboid anatase TiO2 nanocrystals with co-exposed [111]-/{101} facets were synthesized by one-pot method under mild hydrothermal conditions (120~180 ?C) using layered titanate H1.07Ti1.73O4 as precursor and different amounts of HF as morphology-controlling agent. The crystal structure, morphology, microstructure, surface area, electronic states, optical properties and charge migration behavior of xHF-T180 (x = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mL) anatase TiO2 nanocrystals were characterized, and their photocatalytic degradation of MB was evaluated. The results show that, compared with CM-TiO2 and other xHF-T180 anatase TiO2 nanocrystals, 2.5HF-T180 shows the highest k value (0.0165 min-1), which is 18.33, 1.99, 1.31, 1.46, 1.16, 1.27 and 1.34 times that of Blank (0.0009 min-1), CM-TiO2 (0.0083 min-1), 0.5HF-T180 (0.0126 min-1), 1.0HF-T180 (0.0113 min-1), 1.5HF-T180 (0.0142 min-1), 2.0HF-T180 (0.0130 min-1), and 3.0HF-T180 (0.0123 min-1), respectively. The highest photocatalytic activity of 2.5HF-T180 can be attributed to the synergistic effect of its smallest particle size, largest specific surface area, weakest fluorescent intensity and smallest electrical resistance. This study provides a new idea for the synthesis of anatase-type TiO2 nanocrystals with high photocatalytic performance for the treatment of organic dye wastewater.