Fabrication of heterostructured Bi2O2CO3/Bi2O4 photocatalyst and efficient photodegradation of organic contaminants under visible-light.

Heterostructured Bi2O2CO3/Bi2O4 photocatalysts were fabricated by a facile one-pot hydrothermal method, in which melem served as the sacrificial reagent to supply carbonate anions. The as-synthesized Bi2O2CO3/Bi2O4 heterojunction catalysts were characterized by X-ray diffraction, UV-vis diffuse reflectance spectra, X-ray photoelectron spectroscopy, scanning electron microscope, and transmission electron microscope. The XRD patterns of Bi2O2CO3/Bi2O4 catalysts showed the distinctive peaks of Bi2O2CO3 and Bi2O4. The SEM and TEM results showed that the pure Bi2O2CO3 possessed large plate morphology, while Bi2O4 were composed of various nanorods and particles. As for Bi2O2CO3/Bi2O4 heterojunction, it was obviously observed that Bi2O4 nanorods and particles were grown on the surfaces of Bi2O2CO3 plates. The visible light driven photocatalytic activity of Bi2O2CO3/Bi2O4 heterojunction photocatalyst was evaluated by decomposing dyes, phenol, and bisphenol A in water. Compared with Bi2O2CO3 and Bi2O4, the Bi2O2CO3/Bi2O4 photocatalysts have exhibited remarkable enhanced activity under visible light. The excellent activity can be mainly attributed to the enhanced separation efficiency of photo-generated carriers. Controlled experiments using different radical scavengers proved that O2- and h+ played the main role in decomposing organic pollutants. The results of this work would provide a new sight for the construction of visible light-responsive photocatalysts with high performance.