Green Synthesis of Cobalt-Doped CeFe₂O₅ Nanocomposites Using Waste <em>Gossypium arboreum</em> L. Stalks and Their Application in the Removal of Toxic Water Pollutants

Abstract

Currently, there is an increasing need to find new ways to purify water by eliminating bacterial biofilms, textile dyes, and toxic water pollutants. These contaminants pose significant risks to both human health and the environment. To address this issue, in this study, we have developed an eco-friendly approach that involves synthesizing a cobalt-doped cerium iron oxide (CCIO) nanocomposite (NC) using an aqueous extract of Gossypium arboreum L. stalks. The resulting nanoparticles can be used to effectively purify water and tackle the challenges associated with these harmful pollutants. Nanoparticles excel in water pollutant removal by providing a high surface area for efficient adsorption, versatile design for the simultaneous removal of multiple contaminants, catalytic properties for organic pollutant degradation, and magnetic features for easy separation, offering cost-effective and sustainable water treatment solutions. A CCIO nanocomposite was synthesized via a green co-precipitation method utilizing biomolecules and co-enzymes extracted from the aqueous solution of Gossypium arboreum L. stalk. This single-step synthesis process was accomplished within a 5-h reaction period. Furthermore, the synthesis of nanocomposites was confirmed by various characterization techniques such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic light scattering (DLS), and energy dispersive X-ray (EDX) technology. CCIO NCs were discovered to have a spherical shape and an average size of 40 nm. Based on DLS zeta potential analysis, CCIO NCs were found to be anionic. CCIO NCs also showed significant antimicrobial and antioxidant activity. Overall, considering their physical and chemical properties, the application of CCIO NCs for the adsorption of various dyes (~91%) and water pollutants (chromium = ~60%) has been considered here since they exhibit great adsorption capacity owing to their microporous structure, and represent a step forward in water purification.

Keywords

• green synthesis
• co-precipitation
• adsorption
• dye removal
• pollutant removal
• cotton stalks