Novel p–n heterojunction BiOI/CeO2 photocatalyst for wider spectrum visible-light photocatalytic degradation of refractory pollutants
Recently, visible-light-driven photocatalysts have been widely used in environmental pollutant remediation. In the present study, BiOI/CeO2 p–n junction photocatalysts were successfully fabricated using a facile in situ chemical bath method. The BiOI/CeO2 p–n junction photocatalysts exhibited excellent photoactivity for the decomposition of the refractory pollutant bisphenol A (BPA) and methylene orange (MO) under visible light illumination. The sample with a 1 : 1 mole ratio of BiOI : CeO2 possessed the highest photocatalytic performance out of all of the as-obtained catalysts. Mott–Schottky plots indicated that p–n junctions were successfully constructed between BiOI and CeO2. The optical and electrical properties of the materials demonstrate that the introduction of BiOI can broaden the visible-light absorption region of CeO2, and the transfer rate of the electron–hole pairs dramatically improves through forming a p–n junction. Furthermore, the BPA degradation efficiency exhibited excellent photostability after four consecutive cycles. These features show that the BiOI/CeO2 p–n junction has great application potential for refractory pollutant removal from wastewater.