Optical, magnetic and structural properties of ZnFe2O4 nanoparticles synthesized by conventional and microwave assisted combustion method: A comparative investigation

In the present work, zinc ferrite nanostructured materials were synthesized by a microwave combustion method (MCM) using Okra (Abelmoschus esculentus) as a plant extract and compared with the ones synthesized by a conventional combustion method (CCM). Plant extracts play a dual role of both oxidizing and reducing nature. Microwave assisted combustion method is a potential, attractive and energy saving technique when compared to conventional heating, due to the direct heating of the reaction mixtures. They have several advantages, such as, simple, inexpensive, good stability of nanoparticles, less time consumption, and large-scale synthesis. The synthesized products are investigated by the standard characterization techniques, such as, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), Rietveld refinement analysis, high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), photoluminescence studies (PL), diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM), for the structural phase, morphology, optical and magnetic properties. The development of the single cubic phase ZnFe2O4 is affirmed by XRD and FT-IR. The morphological studies of the obtained ZnFe2O4 nanoparticles were investigated by HR-SEM studies. The optical band gap value was determined by DRS. The change in saturation magnetization (Ms) and coercivity (Hc) was observed by VSM studies. Dye Sensitized Solar Cell made up of ZnFe2O4 nanoparticles prepared by microwave method exhibited maximum conversion efficiency of around 0.22%, which is higher than that obtained from conventional combustion method gave efficiency of approximately 0.15%.