Preparation and photocatalytic performance of Br-N codoped TiO₂/magnetic carbon composites

Magnetic activate carbon (MAC) coupled by chitosan-glutaraldehyde crosslinking technique was synthesized by ferric salts chemical precipitation method using activate carbon as raw meterial. Based on MAC, Br-N codoped TiO₂/magnetic carbon composites (Br_x-N-TiO₂/MAC) were prepared by a facile sol-gel method.The synthesized composites were characterized by XRD, UV-Vis diffuse reflectance spectroscopy (DRS), N₂ adsorption-desorption test (BET), SEM and XPS. The photocatalytic activity of the composites was evaluated by photocatalytic degradation of salicylic acid under visible light irradiation. Compared with N-TiO₂/MAC, Br_x-N-TiO₂/MAC has a better photocatalytic performance. The degradation effect of Br_0.35-N-TiO₂/MAC to salicylic acid is the best, and the photocatalytic degradation rate of Br_0.35-N-TiO₂/MAC for 3 h can reach up to 83% after 1 h dark absorption. High concentration of salicylic acid can inhibit the photocatalytic reaction rate of Br_x-N-TiO₂/MAC. After reused for three times, the removal rate of Br_0.35-N-TiO₂/MAC to salicylic acid can still reach 78%, which proves the composites have a good chemical stability.