Preparation, Characterization and Effect of Bi-Doping in ZnFe2O4 on Photodegradation of Rhodamine-B under Visible-Light Irradiation

Abstract Water contamination has become a critical issue due to population growth and urbanization, necessitating advanced techniques for pollution prevention and mitigation. In this study, an efficient Bi-doped ZnFe2O4 (ZFO) photocatalysts with different Bi concentrations (3, 5 and 8 mol%) were prepared using the hydrothermal method. The prepared materials were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (UV-DRS), field emission scanning electron microscopy with energy dispersive X-ray spectra analysis, (FESEM- EDS), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS). XRD, FTIR and XPS confirmed the phase formation and oxidation states of the elements. While FESEM revealed a spherical morphology. The ZFBO-5 (69.62 m2 g-1 ) exhibited a more specific surface area compared to pristine ZFO (42.24 m2g-1 ). The photocatalytic activity (PCA) of all the samples was evaluated using Rhodamine-B (Rh-B) under visible light irradiation. The 5 mol% Bi-doped ZnFe2O4 (ZFBO-5) exhibited the highest photodegradation efficiency which was 2.1 times higher than pristine ZFO. The superoxide and hydroxy radicals were identified as key contributors to the degradation of Rh-B and a plausible degradation mechanism was proposed.