pH-driven phase separation: Simple routes for fabricating porous TiO2 film with superhydrophilic and anti-fog properties

A series of TiO2 surfaces with different pore sizes were easily fabricated via pH-driven phase separation in the sol–gel under template-free conditions. The approach is to obtain TiO2 films with well-defined macropores by utilizing neutralization reaction from acid–base combination. The tuning of solution pH from neutralization could reduce the miscibility of solvent and solute and enable the formation of phase separation. The influence of preparation conditions (ratios of acid-to-base, aging time and solvents) on the pore formation was investigated. The porous TiO2 films prepared through pH-driven phase separation exhibit promising super hydrophilic characteristic anti-fog property.