Eco-Friendly Synthesis of Polyvinylpyrrolidone-Stabilized Cerium Oxide Nanohybrids: Physicochemical Characterizations and Evaluation of Agricultural Applications

Abstract

Green synthesis offers an environmentally preferable route for producing metal oxide nanomaterials while reducing reliance on hazardous reagents and energy-intensive procedures. This study synthesised polyvinylpyrrolidone (PVP)-stabilized cerium oxide (CeO₂) nanohybrids using Murraya koenigii leaf extract as a biogenic reducing and stabilising medium. PVP was incorporated as a capping agent to limit aggregation and improve nanoparticle dispersion. The synthesised nanohybrids were evaluated by UV–Visible spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The characterisation results indicated the formation of crystalline PVP/CeO₂ nanohybrids, interactions between PVP and CeO₂, dispersed particle morphology, the expected elemental constituents, and thermal stability. Agricultural performance was assessed using Vigna radiata seeds exposed to 0, 25, 50, and 100 mg/L of the nanohybrids for 15 days. Germination percentage, radicle length, plumule length, and seedling vigor index were monitored. The 25 mg/L treatment produced 100% germination and the greatest Day 15 radicle and plumule lengths, whereas the 50 and 100 mg/L treatments reduced germination and seedling growth. These findings indicate a concentration-dependent response in which the lower tested concentration supported early seedling development, while higher concentrations were inhibitory. The results support further evaluation of dosage, environmental safety, and performance under greenhouse and field conditions before agricultural use.