Fabrication of ZnFe₂O₄ decorated CdS nanosphere composites with excellent visible light photocatalytic activity

In this study, ZnFe₂O₄/CdS composites have been successfully synthesized from decorating CdS nanospheres with ZnFe₂O₄ nanoparticles by a facile method. With the application of detection techniques such as X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, the crystalline structures, surface morphologies, and physicochemical performances of the samples have been investigated in this study. Photocatalytic activities of ZnFe₂O₄/CdS with different loading ratios under simulated visible light irradiation were discussed with malachite green (MG) as a degradation target. The results showed that 20 wt% ZnFe₂O₄/CdS possessed with the best catalytic activity, and the removal efficiency of MG could reach 96% in 120 min. Mechanistic research indicated that CdS and ZnFe₂O₄ could form a Type II heterojunction with stable interface, which was effective for separating photogenerated carriers. The increasing active sites of CdS after the modification of ZnFe₂O₄ also played a key role in improving the efficiency of photocatalysis.