Mesoporous single crystal titanium oxide microparticles for enhanced visible light photodegradation

Abstract

We report a facile one-step fabrication method of mesoporous single crystal ellipsoidal TiO2 (e-TiO2) microparticles with oxygen vacancies. In this method, hydrogen peroxide was used for the oxidation of titanium plate, and ammonia fluoride was used for the microparticle morphology controlling and pore introducing. Characterizations and calculations have proved that our as-synthesized TiO2 microparticles were in anatase phase with meso pores, single crystal structure and Ti (III) component. UV–vis–NIR spectra have also indicated that the bandgap of the e-TiO2 was 2.4 eV, much lower than typical anatase materials (3.2 eV). Rhodamine B and Methylene blue were introduced as dyes for the photodegradation test of the e-TiO2 compared to commercial P25–TiO2. Our e-TiO2 had better adsorption of both dyes and very high efficiency for the photodegradation of Rhodamine B under visible light illumination, whose kinetic constant is four times as much as P25–TiO2. Thus, the one-step synthesized e-TiO2 has high efficiency for visible light dye photodegradation.