Photo-induced hydrophilicity of brookite TiO2 prepared by hydrothermal conversion from Mg2TiO4

Super-hydrophilic titanium dioxide (TiO2) photocatalysts with some mild oxidizing ability are favorable for the self-cleaning applications on plastic films. In this study, we have focused on brookite TiO2 for such purposes. Brookite TiO2 powders were synthesized by the hydrothermal conversion method using Mg2TiO4 as a precursor. Mg2TiO4 (1 g) and 1 M HCl (30 mL) were put into a polytetrafluoroethylene (PTFE)-lined autoclave. The hydrothermal conversion was conducted at 110–150°C for 24 h. The photocatalytic oxidizing properties of brookite TiO2/silicone films on glass substrates, prepared by the flow-coating method, were measured by methylene blue decomposition, and the photo-induced hydrophilicizing properties were evaluated using the contact angle of water under UV irradiation. The brookite TiO2/silicone film prepared from the sample treated at 150°C exhibited well-balanced properties for self-cleaning applications