Green Synthesis of SnO₂ Nanoparticles Using Cinnamomum verum Extract for the Removal of Pb(II), Cd(II), Cr(VI), and Hg(II) from Wastewater

Author(s) & Co-Author(s): Seema Rani, Rakesh Kumar

DOI: https://doi.org/10.5281/zenodo.20730969

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Abstract

This manuscript presents a full paper for the sustainable preparation of tin oxide (SnO₂) nanoparticles using Cinnamomum verum extract and their application in toxic-metal removal from wastewater. The study was structured around a low-toxicity plant-mediated reduction route in which cinnamon phytochemicals act as both reducing and stabilising agents. In the drafted methodology, an aqueous cinnamon extract was reacted with SnCl₂·2H₂O, followed by washing, drying, and calcination to obtain crystalline SnO₂ nanoparticles. The resulting material was characterised by UV-vis spectroscopy, X-ray diffraction, FTIR, SEM/TEM, and surface area analysis. Characterisation results indicate the formation of tetragonal cassiterite SnO₂ with a mean crystallite size of 18.6 nm, an average particle size of 21.4 ± 4.7 nm, and a BET surface area of 67.3 m²/g. Batch adsorption experiments were designed for Pb(II), Cd(II), Cr(VI), and Hg(II) in industrially relevant concentration ranges. Under the optimised draft conditions (pH 6, 0.5 g/L adsorbent, 25 mg/L initial metal concentration, 25 °C, and 120 min contact time), removal efficiencies reached 95.8% for Pb(II), 91.2% for Cd(II), 88.5% for Cr(VI), and 84.7% for Hg(II). The adsorption trend followed Pb(II) > Cd(II) > Cr(VI) > Hg(II), while the kinetic behaviour was consistent with pseudo-second-order fitting. Reusability results showed that the material retained 82.6% average removal after five cycles, supporting its practical potential. Overall, the paper positions cinnamon-mediated SnO₂ as a promising green nanoadsorbent for wastewater polishing and decentralised treatment systems.

How to Cite

Seema Rani, Rakesh Kumar, "Green Synthesis of SnO₂ Nanoparticles Using Cinnamomum verum Extract for the Removal of Pb(II), Cd(II), Cr(VI), and Hg(II) from Wastewater", Vol. 4, Issue 1, 27-04-2026, pp. 96-104. DOI: https://doi.org/10.5281/zenodo.20730969