The role of surface electrification on the growth and structural features of titania nanoparticles

TiO2particles, prepared by following a sol–gel preparative route, were submitted to hydrothermal steps performed at solution pH values corresponding, respectively, to positive, zero and negative oxide surface charges. After the hydrothermal step all the samples were thermally treated at 300 and 600 °C, for the same length of time 6 h. The powders, both precursors and calcined samples, were characterized for phase composition–crystallinity, particle morphology and surface electrification features. The role played by the particles electrification during the hydrothermal step in affecting the physico-chemical properties of the powders is discussed.