Rapid synthesis of hierarchical BiOCl microspheres for efficient photocatalytic degradation of carbamazepine under simulated solar irradiation

A rapid method was developed for the synthesis of hierarchical BiOCl microspheres via a diethylene glycol (DEG) mediated solvothermal route in 30 mm solvothermal time with the assistance of ultrasound. The physicochemical properties of the obtained samples were charadterized and the results indicated that both DEG and ultrasound influenced the morphology, structure, and surface characteristics of BiOCl catalyst, which further determine their specific photocatalytic performances. The as-synthesized BiOCl exhibited high photocatalytic efficiency towards the degradation of carbamazepine under simulated solar irradiation. Carbamazepine was nearly completely eliminated after 150 mm irradiation. The photocatalytic reaction followed pseudo first-order kinetics, and the reaction rate constant is over 9.48 times greater than that of the commercial TiO2 (P25). The enhanced photocatalytic activities could be attributed to the hierarchical nanostructure, exposed {110} facet, special loose-packed structure, and enriched surface hydroxyl group. Radicals and holes trapping experiments showed that h(+), (OH)-O-center dot, and O-center dot(2)- were involved in the photocatalytic process. The obtained results will provide a new sight for the synthesis of hierarchical BiOCl and broadening its application in the removal of the recalcitrant pharmaceutical contaminants from water. (C) 2014 Elsevier B.V. All rights reserved.