摘要
A ZnFe <sub>2</sub> O <sub>4</sub> -TiO <sub>2</sub> nanocomposite combining p-type ZnFe <sub>2</sub> O <sub>4</sub> and n-type TiO <sub>2</sub> was successfully fabricated. The ZnFe <sub>2</sub> O <sub>4</sub> -TiO <sub>2</sub> nanocomposite greatly enhanced the bisphenol A (BPA) photodegradation under visible light irradiation at 465 ± 40 nm. Loading TiO <sub>2</sub> with 1 wt% of ZnFe <sub>2</sub> O <sub>4</sub> produced high photocurrent and low charge transfer resistance. The photodegradation rate of BPA by ZnFe <sub>2</sub> O <sub>4</sub> -TiO <sub>2</sub> , which was highly dependent on the water chemistry including pH, anions, and humic acid, was 20.8–21.4 times higher than that of commercial TiO <sub>2</sub> photocatalysts. Chloride and sulfate ions enhanced BPA photodegradation mostly due to the production of more radical species; whereas nitrate, dihydrogen phosphate, and bicarbonate ions decreased the photodegradation rate of BPA due to the scavenge of hydroxyl radicals. The photoactivity and recyclability of ZnFe <sub>2</sub> O <sub>4</sub> -TiO <sub>2</sub> in lake water was also assessed. A near complete BPA removal from lake water was observed under visible light irradiation. Furthermore, >90% of photocatalytic activity toward BPA degradation was achieved in 5 cycles of continuous addition of BPA to the lake water. The BPA degradation intermediates were identified by HPLC/MS/MS and possible reaction pathways were proposed. Results clearly demonstrate the excellent visible-light-sensitive photocatalytic degradation of BPA over ZnFe <sub>2</sub> O <sub>4</sub> -TiO <sub>2</sub> composite which has a great application potential for the decomposition of emerging contaminants in impaired waters.