Preparation of Titania Films with Cohered Nanosized Particles Using Improved Liquid Phase Deposition Process

An improved liquid phase deposition method is proposed for the preparation of titania films with cohered particles. This method involves introducing micro-bubbles into the normal LPD process. The micro-bubble plays a role in the film formation process by not only preventing nucleation in the lateral direction but also creating a hot spot by self-crushing. This results in a rugged surface film with cohered nanosized titania particles possessing anatase crystallinity, even in the as-grown film. The lowering of the transition temperature from the anatase phase to the rutile phase takes place in the films deposited by the improved LPD process. For the films prepared via the improved LPD process, a photocatalytic UV light response was observed even in the as-grown film. Furthermore, its activity increases drastically after a 500 °C annealing step, leading to crystallinity improvement and surface area increase.