Enhanced Photocatalytic Activity of Highly Crystallized and Ordered Mesoporous Titanium Oxide Measured by Silicon Resonators

Abstract

Ordered mesoporous TiO2 was synthesized using the combined assembly of soft and hard chemistries method and deposited as a film coating on a micro-cantilever sensor array along with two other types of TiO2 film: one from nanoparticles and one prepared via a sol-gel reaction. After loading methylene blue molecules on the TiO2 films, the films were exposed to ultraviolet radiation. The photocatalytic decomposition of methylene blue was monitored by measuring changes in the resonance frequency of each cantilever. The mesoporous TiO2 film showed higher photocatalytic activity than conventional TiO2 films fabricated from nanoparticles or via a sol-gel reaction; this difference is attributed to the purely anatase crystalline morphology of the mesoporous TiO2 film as well as its well-organized pore structure. The three-dimensionally interconnected pore network facilitates the diffusion of methylene blue molecules to the photocatalytically active sites of the mesoporous TiO2.