Defective TiO2 nanomaterial for photocatalytic degradation of carbamazepine drug

Abstract

The remarkable optical properties of defective TiO2 make it an exceptional photocatalyst showing high photocatalytic activity under ultraviolet–visible (UV–Vis) and near-infrared (NIR) irradiations. Herein, a facile technique is provided to synthesize colored TiO2 by degassing TiO2 obtained by a microwave-assisted hydrothermal method. The optical bandgap of TiO2 was shifted from 3.2 eV to 3.06 eV with the formation of new energy levels located below the conduction band at about 1.96 eV. The defective TiO2 was investigated for the photocatalytic degradation of carbamazepine, one of the persistent drugs in water systems and an emerging environmental concern. The highest photocatalytic degradation rate (94.6%) was achieved within 240 min under sunlight irradiation, while 66.3% and 80.7% of 20 ppm CBZ were degraded within 360 min under simulated solar light and visible light. Moreover, the total organic carbon (TOC) analysis demonstrates that about 88.84% was mineralized within 240 min under sunlight irradiation. This modification strategy of TiO2 is found to be one of the best available pathways to achieve a high photocatalytic performance of TiO2 under sunlight irradiation for the degradation of non-removed drugs such as carbamazepine in wastewater treatment plants.