<p>This research introduces a new method for synthesizing a ternary nanocomposite consisting of cerium, cobalt oxides, and carbon nitride nanosheets through an ultrasonic process. The formation and composition of the nanocomposite material were validated through various characterizations, including X-ray diffraction, FTIR, SEM, TEM, and EDX analysis. The nanocomposite’s adsorption properties were assessed for lead ion removal from an aqueous solution, with evaluations of pH and initial adsorbate concentration effects. The findings demonstrate that the adsorption process is influenced by pH and initial concentration, achieving a maximum adsorption capacity of 503.49&#xa0;mg. g⁻¹. The removal of Pb²⁺ ions occur through a chemisorption process that adheres to Elovich kinetics and is accurately represented by the Sips adsorption model. The examination of thermodynamic parameters indicates that both ΔG° and ΔH° are negative. Consequently, adsorption occurs spontaneously and exhibits an exothermic characteristic. A plausible mechanism for the adsorption of lead ions onto the surface of Co₃O₄@CeO₂@g-C₃N₄ nanostructure is proposed. This study indicates that the Co₃O₄@CeO₂@g-C₃N₄ constitute a stable, efficient, and recyclable nanocomposite for the sorption of Pb²⁺. The properties of the nanocomposite and its synthesis process offer a cost-effective and efficient approach to wastewater remediation.</p>