Preparation of ZnFe2O4/ZnO composite: Effect of operational parameters for photocatalytic degradation of dyes under UV and visible illumination

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2020-03, Vol.390, p.112305, Article 112305
• Main Authors: Zouhier, Morad, Tanji, Karim, Navio, J.A., Hidalgo, M.C., Jaramillo-Páez, C., Kherbeche, Abdelhak
• Format: Article
• Language: English
• Subjects: Iron doped ZnO; Methylene blue; Photocatalysis; Remazol brilliant blue; Zinc oxide; ZnFe2O4
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2019.112305

[Display omitted] •Coupled ZnFe2O4/ZnO photocatalyst prepared by solution combustion method.•Enhancement photocatalytic activity of ZnFe2O4/ZnO with respect to pristine ZnO.•The photocatalytic activity of ZnFe2O4/ZnO differs markedly under different operational conditions.•ZnFe2O4/ZnO is a promising photocatalyst for dyes degradation under sun light illumination. An ZnFe2O4/ZnO composite catalyst was prepared by solution combustion method. In this study, one nominal molar percentage of iron was used in the synthesis, corresponding to 20 % molar relative to ZnO. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray Fluorescence (XRF), Scanning Electronic Microscopy (SEM), Transmission Electronic Microscopy (TEM) and Ultraviolet-visible (UV–vis) diffuse spectroscopy (DRS). The photocatalytic activities of the catalysts were investigated based on the degradation of two dyes, methylene blue (MB) and remazol brilliant blue (RBB), in aqueous solution under both UV and visible light illumination respectively. It was found that the composite had a good photocatalytic activity at basic pH by using 1 g/L of catalyst under UV illumination for both MB and RBB. Under visible illumination, while pristine ZnO showed no activity, the composite exhibited an excellent visible efficiency, reaching up to an 80 % conversion of the initial dye concentrations in 2 h. The enhancement of the visible photocatalytic activity of Fe/ZnO sample with respect to pristine ZnO is attributed to the formation of ZnFe2O4 coupled with ZnO, having a narrow band gap value that contributes to the absorption of visible photons with an improved separation path for the photo-generated carriers.