Fabrication of hierarchical BiOI/Bi2MoO6 heterojunction for degradation of bisphenol A and dye under visible light irradiation

Abstract

A novel hierarchical BiOI/Bi2MoO6 composites are prepared by a facile precipitation–deposition method. The prepared photocatalyst was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectrometer (XPS). The resulting BiOI/Bi2MoO6 composites exhibit excellent photocatalytic activity and stability towards the degradation of methylene blue (MB) and bisphenol A (BPA) in aqueous solution under visible light irradiation. The optimal composite with 25% BiOI content shows the highest photocatalytic activity for MB degradation. The enhanced photocatalytic activity is mainly attributed to the formation of BiOI/Bi2MoO6 heterojunction that can facilitate the separation and transfer of the photo-generated charge carriers. The roles of active species in the photocatalytic process are discussed by using different types of active species scavengers. Meanwhile, combined with the photoluminescence (PL) and electrochemical impedance spectroscopy (EIS), the degradation mechanism of the photocatalysts is proposed. It is hoped that the work could provide valuable information on the design of specific structure materials with more excellent properties and set the foundation for the further industrial application.