Novel Magnetic Carbon Nanotube-TiO2 Composites for Solar Light Photocatalytic Degradation of Pharmaceuticals in the Presence of Natural Organic Matter

Abstract

Magnetic carbon nanotube-TiO2 (MCNT-TiO2) composites that rely on the inherent magnetic properties of carbon nanotubes were synthesized and their photocatalytic activity was evaluated for the degradation of carbamazepine and sulfamethoxazole under solar irradiation and environmentally relevant conditions. Compared with a TiO2 reference catalyst, the MCNT-TiO2 composites exhibited a higher photodegradation rate due to the high surface area and extended visible light absorption. The photodegradation rate constants for carbamazepine and sulfamethoxazole in pure water were ˜1.5 and ˜1.2 times greater than those for TiO2, respectively. The catalysts were tested in the presence of natural organic matter and rapid photodegradation rates for carbamazepine and sulfamethoxazole were observed relative to bare TiO2, indicating that MCNT-TiO2 may be suitable for practical applications. Solar and UVC reactivation were used to recover the photocatalytic activity, and UVC irradiation was more efficient and maintained the performance of MCNT-TiO2 for consecutive treatment cycles. MCNT-TiO2 with its unique fast kinetics and high photodegradation activity toward micropollutants exhibits great potential as an alternative method for water and wastewater treatment.