Effect of isopropanol on crystal growth and photocatalytic properties regulation of anatase TiO2 single crystals

Abstract

ABSTRACTAnatase TiO2 crystals with different morphologies were synthesised through a solvothermal route and characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and selected-area electron diffraction (SAED). Characterisation results show that anatase TiO2 single crystals with high activity (001) facets could be synthesised by using hydrofluoric acid as the crystal plane controlling agent. Experiments on the effect of isopropanol (i-PrOH) on crystal growth show that isopropanol can accelerate hydroxylation and substitution of (001) facets under solvothermal conditions, resulting in corrosion of (001) facets. Besides, we proposed and discussed a plausible effect mechanism of isopropanol on crystal growth. Research on the regulation of photocatalytic properties proposed that the solvents properties are the critical factors in controlling the redox reaction process. The stronger acidic conditions and higher proportion of water in solvents are more conducive to oxidation reaction. Anaerobic environment is more conducive to reduction reaction.