Green synthesis of Ag–CoFe₂O₄ nanocomposites by Taxus wallichiana leaf extract for adsorption of Pb⁺² ions from aqueous solution

In this study, the synthesis of silver–cobalt ferrite (Ag–CFO) was achieved through a novel approach using Taxus wallichiana leaf extract as a potent reducing agent. By strategically varying the concentrations of silver and cobalt ferrite, Ag–CFO nanocomposites with different ratios were successfully synthesized. Various analytical techniques were used to characterize the adsorbents. XRD confirmed the structure and crystallite sizes were found in the range  40 to 48 nm. The purity of the synthesized material was affirmed through energy-dispersive X-ray (EDX) analysis. The impact of pH, concentration, and temperatures on the adsorption of Pb⁺² ions from aqueous solutions were performed. The maximum adsorption capacity and binding strength of Pb⁺² ions were evaluated by employing different models such as Freundlich, Langmuir, and Temkin. For selectivity, various solutions of divalent metal cations like Zn²⁺, Ni²⁺, Cd²⁺, and Pb²⁺ in the concentration range 5–100 mg/L were used. Delving into the thermodynamics process, the study identified the nature of adsorption as primarily physical. The desorption study was undertaken in the presence of 2-M H₂SO₄ and 2MNaOH. This study, therefore, provided a successful path to use Ag–CFO NCs as a potential adsorbent for environmental remediation.