THE Comparative Study of Nanostructured 3d and 4d Transition Metal Oxides (Mn₂O₃ and TiO₂) for Energy, Environmental, and Biomedical Applications: Synthesis, Characterization, and Future Perspectives

nanomaterials

Abstract

This comparative study investigates the synthesis and characterization of Mn₂O₃ and TiO₂ nanoparticles using auto-combustion and sol-gel methods, respectively. The structural, morphological, and compositional properties of both nanoparticles were analyzed using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) spectroscopy. The XRD analysis revealed distinct crystal structures, with Mn₂O₃ exhibiting a cubic structure (space group la3 ̅, lattice parameter a = 9.410086 Å) and TiO₂ displaying a tetragonal anatase phase (space group I41/amd, lattice parameters a = b = 3.771 Å and c = 9.43 Å). The average crystallite size of Mn₂O₃ nanoparticles was estimated to be approximately 30 ± 5 nm using the Debye-Scherrer equation, whereas the Williamson-Hall plot revealed a crystallite size of 75 ± 5 nm and lattice micro-strain of 0.00181. In contrast, TiO₂ nanoparticles exhibited irregular and spherical shapes with clumped distribution, having average grain sizes of 0.54 µm and 0.31 µm under 10,000X and 5,000X magnifications, respectively. EDX analysis detected the presence of Ti, O, and a small amount of S impurities in TiO₂ nanoparticles. The comparative analysis highlights the differences in structural, morphological, and compositional properties between Mn₂O₃ and TiO₂ nanoparticles, which can significantly impact their potential applications in various fields, including energy storage, catalysis, and biomedicine. This study provides valuable insights into the synthesis and characterization of these nanoparticles, paving the way for further research and development.