Biogenic Production and Physicochemical Characterization of ZnO Nano Fertilizer from Punica Granatum Peel Extract and their Impact on Sorghum Bicolor Growth

Abstract

The present study focused on the green synthesis, characterization, and agricultural application of zinc oxide (ZnO) nanoparticles using Punica granatum (pomegranate) peel extract as a natural reducing and stabilizing agent. The synthesized ZnO nanoparticles were characterized using UV–Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). UV–Visible spectroscopic analysis showed a characteristic absorption peak is 350-360 in the UV region, confirming the formation of ZnO nanoparticles due to surface plasmon resonance. FTIR analysis revealed the presence of various phytochemicals such as phenols, flavonoids, and other functional groups responsible for the reduction and stabilization of nanoparticles. XRD analysis exhibited distinct diffraction peaks corresponding to the hexagonal wurtzite crystalline structure of ZnO nanoparticles, confirming their crystalline and pure nature. SEM analysis demonstrated predominantly quasi-spherical to irregular morphology with slight agglomeration and nanoscale particle size distribution. The biosynthesized ZnO nanoparticles were further evaluated for their nanofertilizer effect on sorghum (Sorghum bicolor) seed germination and plant growth. The ZnO nanofertilizer treatment significantly improved seed germination, root and shoot, and overall plant growth compared to untreated control plants. The enhanced growth performance may be attributed to improved nutrient uptake, higher surface area, and efficient zinc availability provided by the nanoparticles. The study concludes that green synthesized ZnO nanoparticles derived from Punica granatum peel extract possess promising structural and morphological properties and can be utilized as an eco-friendly and sustainable nanofertilizer for enhancing sorghum growth and agricultural productivity.

Introduction

This study focuses on improving agricultural sustainability by developing eco-friendly zinc oxide (ZnO) nanofertilizers using green synthesis methods. Conventional chemical fertilizers often lead to low nutrient efficiency and environmental pollution, while zinc deficiency in soils significantly reduces crop yield and quality. To address this, the research uses nanotechnology to enhance zinc delivery to plants in a more efficient and sustainable way.

ZnO nanoparticles were synthesized using Punica granatum (pomegranate) peel extract, which acts as a natural reducing and stabilizing agent. The extract is rich in bioactive compounds like flavonoids and phenolics, making it suitable for environmentally friendly nanoparticle production. The synthesized nanoparticles were then characterized using UV-Vis spectroscopy, FTIR, SEM, and XRD, confirming successful formation of crystalline, hexagonal ZnO nanoparticles with suitable size and morphology.

The effectiveness of the ZnO nanofertilizer was tested on Sorghum bicolor seeds under laboratory conditions. Results showed significant improvements compared to untreated seeds, including higher germination rates, increased root and shoot length, improved seed vigor, and greater chlorophyll content. These improvements are linked to better zinc availability, which enhances enzymatic activity, photosynthesis, and overall plant growth.

Conclusion

The present study successfully demonstrated the green synthesis of zinc oxide (ZnO) nanoparticles using Punica granatum peel extract as an eco-friendly and sustainable reducing and stabilizing agent. Characterization studies confirmed the successful formation of ZnO nanoparticles. UV–Visible spectroscopy revealed the characteristic absorption peak of ZnO nanoparticles, while FTIR analysis confirmed the involvement of phytochemicals such as phenols and flavonoids in nanoparticle synthesis and stabilization. XRD analysis verified the highly crystalline hexagonal wurtzite structure of ZnO nanoparticles, and SEM analysis showed predominantly quasi-spherical to irregular morphology with slight agglomeration in the nanoscale range. Furthermore, the synthesized ZnO nanoparticles exhibited significant nanofertilizer potential by enhancing seed germination percentage, root length, shoot length, seed vigor index, biomass accumulation, and overall growth performance of sorghum (Sorghum bicolor) compared to untreated control plants. The improved plant growth may be attributed to enhanced zinc availability, increased surface area, and efficient nutrient uptake provided by the nanoparticles. The findings suggest that biosynthesized ZnO nanoparticles derived from agricultural waste such as pomegranate peel can serve as an effective, low-cost, and environmentally friendly nanofertilizer for sustainable agricultural applications. This study highlights the potential of green nanotechnology in improving crop productivity while reducing dependence on conventional chemical fertilizers.

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Copyright © 2026 Amarvani P Kanjikar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.