Facile ion-exchange synthesis of BiOI/Bi2O2CO3 heterostructure for efficient photocatalytic activity under visible light irradiation

The BiOI/Bi2O2CO3 heterostructural photocatalysts were synthesized by a facile ion-exchange route between Bi2O2CO3 precursor and KI with ultrasonic reaction. The as-prepared BiOI/Bi2O2CO3 heterostructures were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance absorption spectra (DRS), fourier transform infrared spectroscopy (FTIR) and photoluminescence spectra (PL). The BiOI/Bi2O2CO3 heterostructures exhibited much higher photocatalytic activities than those of single Bi2O2CO3 and BiOI for the degradation of Rhodamine B (RhB) under visible light irradiation. The significantly enhanced photocatalytic activity of BiOI/Bi2O2CO3 heterostructures could be attributed to the formation of p-n heterojunction between p-type BiOI and n-type Bi2O2CO3, which effectively separated the photogenerated electron-hole pairs. The possible mechanism of BiOI/Bi2O2CO3 heterostructures as photocatalysts was proposed.