Preparation and characterization of bicrystalline TiO2 photocatalysts with high crystallinity and large surface area

Anatase–brookite bicrystalline TiO2 photocatalysts were successfully synthesized by a surfactant-assisted sol–gel route. Cetyltrimethylammonium chloride and tetra-n-butyl titanate were used as a surfactant and a titanium precursor, respectively. The bicrystalline TiO2 photocatalyst samples were aged at different temperatures (RT ~ 100 °C) and were found to have different morphologies, crystallinities, and surface areas. The photocatalytic activity of each sample was investigated by measuring the photodecomposition of reactive black 5 (RB5) and rhodamine B (Rho B). The photodecomposition rate ([k] = 1.396 h− 1) of the sample prepared at 100 °C was twice as high as that of Degussa P25 ([k] = 0.707 h− 1) and three times as high as that of 5-nm-sized anatase TiO2 particles ([k] = 0.471 h− 1).

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► An anatase–brookite bicrystalline TiO2 photocatalyst was synthesized. ► The bicrystalline TiO2 photocatalyst was aged at different temperatures. ► The photocatalytic activity was investigated by photodecomposition of azo dyes.