Sunlight driven photocatalytic degradation of RhB dye using composite of bismuth oxy-bromide kaolinite BiOBr@Kaol: Experimental and molecular dynamic simulation studies

Abstract

This study reported the synthesis of a new eco-friendly photocatalyst nanocomposite based on kaolinite clay and bismuth oxybromide (BiOBr@Kaolinite) using a facile co-precipitation method in acidic medium. The prepared nanocomposite was characterized using several techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning microscopy electron (SEM), Transmission electron microscope (TEM), Energy-dispersive X-ray spectroscopy (EDX), UV–Vis diffuse reflectance spectra (DRS), and X-ray photoelectron spectroscopy (XPS). These techniques were used to determine the crystal phase, functional groups, morphology, elementary composition, chemical states, optical properties, and bad gap energy of as synthesized, respectively. The characterized materials were then applied for rapid photodegradation of Rhodamine B dye (RhB), indicating its effective use for the degradation of toxic organic pollutants under sunlight irradiation. The photocatalytic activity study showed that RhB dye (10 mg/L) was degraded within 30 min under sunlight irradiation. The degradation mechanism of RhB and the photocatalytic stability study of the nanocomposite BiOBr@0.4Kaol showed that, the high photocatalytic activity could be attributed to the charge transfer from kaolinite to BiOBr nanoparticles, which prevented the rapid recombination of the electron-hole pair induced during the photocatalytic process. Moreover, MD and DFT-D stimulations and adsorption calculations based on Monte Carlo were applied in this study. This study led to the development of an effective and environmentally friendly photocatalyst nanocomposite for the degradation of toxic organic pollutants in wastewater, highlighting its potential application in water treatment and depollution processes.