Influence of waste battery-derived Zn²⁺ doping on the structural, optical and photo-Fenton-like catalytic properties of Fe₂O₃ nanostructures

Research on waste-derived nanomaterials with applications have much interest. In this study, the synthesis of waste battery derived zinc (Zn²⁺)-doped Fe₂O₃ (Zn-Fe₂O₃) nanostructures was reported. The structural, and optical characteristics of Zn-Fe₂O₃ samples were analysed by different analytical techniques. The presence of Fe, Zn, and O elements were confirmed by EDS. X-ray diffraction (XRD) results confirmed Zn²⁺ doping in Fe₂O₃ lattices, whereas Fourier transform infrared (FTIR) results supported the formation of α-Fe₂O₃. The morphology and particle size of Zn-Fe₂O₃ samples were deduced from high resolution scanning electron microscopic (HRSEM) analysis. XPS result infers the oxidation state of iron, zinc and oxygen in 5 %Zn-Fe₂O₃. The band-gap of Zn-Fe₂O₃ samples were determined by UV–visible analysis. The catalytic potential of Zn-Fe₂O₃ samples was tested by visible light induced photocatalytic degradation of methylene blue. The influence of H₂O₂ (hydrogen peroxide) in the photocatalytic property of Zn-Fe₂O₃ samples was further evaluated. 5 %Zn-Fe₂O₃ and 2 %Zn-Fe₂O₃ exhibited 87 % and 98.9 % efficiency in photocatalysis and photo-Fenton like catalysis, respectively. The possible photo-Fenton mechanism of 2 %Zn-Fe₂O₃ has been deduced.