Structural and Morphological Properties of Biosynthesized Zinc Oxide Nanoparticles: as a Promising Nanomaterial for Energy Conversion Devices

The sustainable development of recent materials in nanotechnology has led to an extensive search for viable, eco-friendly, and toxic-free materials to improve the power conversion efficiency of existing optical devices. The biosynthesis of ZnO nanoparticles was achieved using a water extract of Moringa oleifera leaves and characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and UV-Vis spectroscopy. XRD analysis confirmed that the nanoparticles exhibit a hexagonal wurtzite crystal structure, with grain sizes ranging from 6.757 nm to 21.51 nm, indicating high phase purity. The optical absorption in the UV–visible range shifts from approximately 370 nm to 400 nm, corresponding to a reduction in bandgap energy from 1.22 eV to 1.1 eV. FT-IR spectral analysis and chemical bonding studies confirmed the successful formation of zinc oxide nanoparticles (ZnONPs). The crystallite structure and growth were found to be significantly influenced by the annealing temperature. The results demonstrate that the properties of ZnO nanoparticles (ZnONPs) can be effectively tailored by adjusting the annealing temperature, making them promising candidates for use in renewable energy device applications