Synthesis and characterization of B-doped TiO2 and their performance for the degradation of metoprolol

Abstract

Pure and B-doped TiO2 photocatalysts were synthesized by sol–gel method. Boric acid was used as boron source and titanium tetra-isopropoxide as TiO2 precursor. Nominal boron/titania proportions were in the range 0–9% (w/w). The powder was characterized by X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM), UV–vis absorption spectra, BET specific surface area, X-ray photoelectron spectroscopy (XPS) and zeta potential.The β-blockers are pharmaceuticals frequently detected in waters. Among these β-blockers, metoprolol (MET) is one of the most commonly used for the treatment of a variety of cardiovascular diseases, thus being necessary the search for methods able to remove it. In this context, the photocatalytic reactivity of the synthesized catalysts was evaluated by its use in MET photodegradation using a solar simulator with xenon lamp as irradiation source. Results showed that the 5% (w/w) B-doped TiO2 exhibited greater photodegradation (70% MET removal) than pure TiO2 (48% MET removal). Some factors were responsible for the photocatalytic performance of B-doped TiO2 which include the high surface area, mesoporous structure, anatase–rutile crystalline structure, formation of Ti(III), introduction of boron as a B–O–Ti species and uniformity in particles surface size.