Efficient Waste Management: Harnessing SnO2─CuO─Li0.5Fe2.5O4 Heterojunction for Advanced Photocatalysis

This research investigates photodegradation of indigo carmine dye using a novel SnO2─CuO─Li0.5Fe2.5O4 nanocomposite. SnO2 and CuO were synthesized via the co-precipitation method, while Li0.5Fe2.5O4 (LFO) was prepared through the auto-combustion method. Three different magnetic nanocomposites (25Sn/50Cu/25LF, 50Sn/25Cu/25LF, 25Sn/25Cu/50LF) were prepared by calcining the mixtures at 350°C for 3 h. Phase formation of the as-synthesized materials was analyzed by powder x-ray diffraction (XRD) studies. Optical band gaps were investigated using diffuse reflectance spectra (DRS). Band gaps of all compounds were observed in the visible range (1.65–3.63 eV). Morphology and microstructures were analyzed using FESEM and TEM. Elemental compositions of the samples were studied using EDS. Photocatalytic degradation of indigo carmine was conducted under sunlight irradiation for 3 h. Photodegradation efficiencies were 10% for SnO2, 73% for CuO, and 12% for LFO under sunlight irradiation in 180 min. Complete degradation was achieved for 50Sn/25Cu/25LF at pH 10.2, using 0.15 g of the catalyst under sunlight exposure within 30 min. Reusability over three cycles showed significant efficiency, that is, 96% for cycles 2 and 3.