Effect of Na2SiO3 on synthesis of TiO2 nanopowders by thermal processing of the precursor

TiO2 nanopowders could be prepared by thermal processing of the precursor of titanium hydroxide, urea and Na2SiO3. The powders were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The results show that Na2SiO3 has an important effect on the average crystallite size and dispersity of TiO2 nanopowders, and other phases (Na2SO4 and SiO2) will be introduced. However, Na2SO4 has distinctive intercalation ability and catalytic activity; SiO2 coating layers can effectively inhibit the agglomeration of TiO2 nanopowders. TiO2 (anatase) powders with well dispersity can be prepared at ∼600 °C for 2 h with addition of 2–6 wt.% Na2SiO3, and the average crystallite size is 15.5–22.1 nm. The surface of the sample mainly consists of Ti, O, C, Si, Na and S six species elements.