Synthesis and photocatalytic redox properties of anatase TiO2 single crystals

The anatase TiO2 single crystals were synthesized through a solvothermal route and their morphology and structure were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Energy Dispersive X-ray Spectrometer (EDX). Characterization and photocatalytic activity experiments proposed that the simultaneous exposure of (001) and (101) facets could facilitate charge separation. While, due to the effect of surface substitution, the (001) facets were easier to be corroded with the increasing synthesis time. Moreover, the as-synthesized anatase TiO2 single crystals with (001) facets showed superior photocatalytic oxidation properties. Besides, the research on the plausible competitive mechanism of oxidation and reduction in the same reaction system suggested that the oxidation reaction was the predominant one with the increasing proportion of water on anatase TiO2 single crystals possessing the high reactivity of the (001) facets. (C) 2016 Elsevier B.V. All rights reserved.