Preparation of nanoanatase and its in situ XRD study

Phase pure nanoanatase was prepared by sol-hydrolysis of TiCl4 in ammonium sulfate solution. In order to investigate the microstrain effect on nanoanatase transformation, the transformation process of the sample was investigated by in situ XRD. Based on the in situ XRD data, a variation of the diameter and its distribution, and the microstrain of nanotitania particles were estimated with Win XRD software. The results show that the transformation process of nanoanatase can be divided into four steps; a rate competition between the anatase growth and the transformation from anatase to rutile determines the diameter and its size distribution of anatase nanoparticles; and during the phase transformation, the microstrain determines the rates of anatase growth and its transformation.