Efficient mesoporous anatase-brookite TiO2 photocatalysts for degradation of ibuprofen

Abstract

Mesoporous anatase-brookite heterojunction TiO2 photocatalysts with tunable brookite/anatase ratios controlled by glycine assistant were successfully synthesized by facile hydrothermal process. In addition, pure brookite phase was prepared in the absence of glycine. The obtained TiO2 catalysts have been characterized by X-ray diffraction, Brunauer-Emmett-Teller analysis, transmission electron microscope and field emission-scanning electron microscopy. The X-ray diffraction revealed the formation of brookite-phase either in pure form in the absence of glycine or in mixing with anatase in the presence of glycine. The field emission-scanning electron microscopy micrograph of pure brookite indicated the formation of spindle-like structures with particle size ∼ 25 nm. The transmission electron microscope image of the optimum sample indicated the formation of small quasi-spherical particles and rod-like particles. N2 isotherm measurements confirmed that anatase/brookite TiO2 materials have mesoporous structure. The photocatalytic degradation of ibuprofen with low concentration was investigated using these novel TiO2 materials under UV irradiation light for water treatment. The anatase/brookite TiO2 samples showed a superior photocatalytic activity compared to pure brookite TiO2 sample. Sample containing 74.4% anatase/25.6 brookite displayed the highest photocatalytic activity for ibuprofen degradation (98.9 %) under UV light for 120 min due to the synergistic effect between anatase and brookite phases, high surface area (72.4 m2 g−1) and mesoporous structure.