Cu-TiO_2 nanorods with enhanced ultraviolet- and visible-light photoactivity for bisphenol A degradation

摘要

In this study, the microwave-assisted sol-gel method and chemical reduction were used to synthesize Cu-TiO_2 nanorod composites for enhanced photocatalytic degradation of bisphenol A (BPA) in the presence of UV and visible lights. The electron microscopic images showed that the Cu nanoparticles at 4.5 ±0.1 nm were well-deposited onto the surface of TiO_2 nanorods after chemical reduction of Cu ions by NaBH_4. The X-ray diffractometry patterns and X-ray photoelectron spectroscopic results indicated that Cu species on the Cu-TiO_2 nanorods were mainly the mixture of CU_2O and Cu~°. The Cu-TiO_2 nanorods showed excellent photocatalytic activity toward BPA photodegradation under the irradiation of UV and visible lights. The pseudo-first-order rate constant (k_(obs)) for BPA photodegradation by 7wt% Cu-TiO_2 nanorods were 18.4 and 3.8 times higher than those of as-synthesized TiO_2 nanorods and Degussa P25 TiO_2, respectively, under the UV light irradiation. In addition, the k_(obs) for BPA photodegradation by 7 wt% Cu-TiO_2 nanorods increased by a factor of 5.8 when compared with that of Degussa P25 TiO_2 under the irradiation of 460 ±40 nm visible light. Results obtained in this study clearly demonstrate the feasibility of using one-dimensional Cu-TiO_2 nanorods for photocatalytic degradation of BPA and other pharmaceutical and personal care products in water and wastewater treatment plants.