Effect of synthesis conditions on the photocatalytic activity of titanium dioxide nanomaterials

The photocatalytic activity of nanosized titanium dioxide powders synthesized by thermal treatment of the precursor phases precipitated from aqueous solutions on the degradation of methylene blue in a solution under the action of UV radiation has been studied. The dependence of the photocatalytic activity on pH of the medium used to precipitate precursor phases in combination with temperatures and duration of their thermal treatment has been found. The selected synthesis conditions allowed to obtain titanium dioxide materials that appear to be at least two times more active than the commercial catalyst Degussa P25. It is found that the materials based on anatase modification of titanium dioxide obtained from the phases precipitated at pH 7–9 and calcined at 600°C for 1–2 h show the highest photocatalytic activity. It is shown that under UV radiation 25 min is enough for almost complete destruction of methylene blue dye in the solution with an initial concentration of 20 mg/L.