Influence of solution chemistry on the properties of hydrothermally grown TiO2 for advanced applications

It is demonstrated that the properties of hydrothermally deposited titanium (IV) oxide (TiO2) films are greatly affected by the solution chemistry. Anatase TiO2 films grown using i-PrOH presented the best reversible photoinduced hydrophilic response, reaching a contact angle (CA) of 15° and 83% photocatalytic activity as well as measurable photoconductivity. Inclusion of as low as 0.02 M NaOH in the solution resulted in films probably consisted of sodium titanate exhibiting good photoinduced properties, which makes it a promising candidate for various applications. In contrast, rutile TiO2 films prepared using EtOH as a solvent showed weak photoinduced activity. The correlation of solution chemistry with the morphology and the photoinduced properties of the materials are discussed.