A Density Functional Theory Study Of Anatase TiO₂Nanocrystal’s Morphology And Surface Properties In Solution

Density functional theory calculations have been performed to study the factors that affect the morphology and surface properties of anatase TiO2in solution. The dissociated form of the hydrogen-fluoric(HF) and hydrogen-chloride(HCl) adsorbed on the TiO2facets have been obtained and the adsorption energies were estimated. The TiO2(001) facet is found to be the most stable one for the adsorption of HF and HCl. Then the surface energies of HF/HCl-covered facets were calculated by our method to get a quantitative interpretation for the growth mechanism of TiO2nanocrystal in solution.The aqueous solution is the inevitable and important factor for the crystal’s growth under real conditions. So the DFT method have been performed to study this important fator. The solvation energies of periodic slab were calculated by SIESTA and Gaussian03. These data were used in the calculated systems of ESPRESSO. We get the surface energies of covered facet in the effect of aqueous solution. The inclusion of aqueous solution influence makes the results more accurate and gives better agreement with the experimental phenomenon. We also employed the calculated method on other TiO2nanocrystals with different morphologies and obtained good results.