SnO₂/TiO₂ bilayer thin films exhibiting superhydrophilic properties

Nanostructured thin films of TiO₂, SnO₂, and SnO₂/TiO₂ have been deposited by sol-gel method. The films are characterized by X-ray diffraction, wettability and optical properties. In the present work, we have achieved a way of converting hydrophilic to super-hydrophilic state by incorporating TiO₂ buffer layer in between substrate and SnO₂ film, which has its utility in anti-fogging surfaces. The decrease in contact angle of water over SnO₂/TiO₂ bilayer is attributed to the increase in roughness of the film as well as surface energy of the substrate.