XRD and FTIR Characterization of Mixed Metal Oxide Nanoparticles Synthesized via Grape Leaf Powder-Assisted Calcination

Abstract

Mixed metal oxide nanoparticles have gained significant attention due to their enhanced physicochemical properties compared to single metal oxides. In the present study, Co-Ni-Zn and Ni-Fe mixed metal oxide nanoparticles were successfully synthesized using a green synthesis approach with grape leaf powder as a natural reducing and stabilizing agent, followed by calcination at 500°C to achieve crystalline oxide formation. The structural properties of the synthesized materials were systematically investigated using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). XRD analysis confirmed the formation of nanocrystalline phases with crystallite sizes in the range of 50–70 nm. The Co-Ni-Zn system exhibited three distinct phases corresponding to Co₃O₄, NiO, and ZnO, while the Ni-Fe system showed the formation of NiO and Fe₂O₃ phases with possible NiFe₂O₄ spinel formation. FTIR spectra revealed characteristic metal–oxygen (M–O) stretching vibrations confirming the establishment of stable oxide lattices in both samples. The Ni-Fe sample exhibited additional M–O bands at 668 cm⁻¹, indicating spinel ferrite formation, along with fewer organic residues compared to the Co-Ni-Zn sample, suggesting better thermal decomposition and higher purity. The presence of phytochemical-related C–O stretching vibrations confirmed that grape leaf powder components act as effective capping agents, preventing nanoparticle agglomeration. The combined results demonstrate the successful synthesis of nanostructured mixed metal oxide systems with good crystallinity and stable surface chemistry using an environmentally benign approach