Sustainable and eco-philic method for the detoxification arsenic from polluted water using green synthesised cubic ceria nanoparticles

Biogenic cerium oxide nanoparticles (CeO 2 NPs) were prepared using Punarnava leaf extract and evaluated for arsenate (As(V)) removal from aqueous solutions. Structural and surface characterizations (XRD, FTIR, SEM–EDX, TEM, BET, and XPS) confirmed the formation of crystalline, nanosized CeO 2 with mesoporosity and abundant surface hydroxyl groups. Batch adsorption studies demonstrated high removal efficiency across a broad pH range (2–10), with maximum uptake at pH 5, achieving 99% removal. The equilibrium adsorption capacity reached 863.7 mg/g. Adsorption results fitted well with the Freundlich isotherm and pseudo-second-order kinetic model, indicating multilayer adsorption and chemisorption. Competitive ion studies showed minimal interference, with only slight effects from sulphate, phosphate, fluoride, cyanide, and nitrate. The material demonstrates strong adsorption capacity for arsenate ions, even when present in low concentration. Morphological changes in SEM images and the detection of arsenic signals in EDX spectra confirmed successful adsorption. Overall, CeO 2 NPs exhibit exceptional potential as a sustainable, high-capacity adsorbent for arsenic remediation in real water systems.