The poisoning of natural water resources by waste discharge is a significant problem, and the search for a solution to a problem of this magnitude is a matter of concern on a global scale. Novel Fe2O3@Al2O3 nanocomposite was synthesized via a simple, green, and eco-friendly method utilizing glucose as a capping material. Transmission electron microscopy (TEM) results for the synthesized Fe2O3@Al2O3 revealed a particle size ranging between 3.5 and 13.9 nm. The sorbent possessed a specific surface area of 113.46 m2 g-1 and was tested for removing heavy metals from water, exemplified by Pb2+. Fe2O3@Al2O3 was proven to be an excellent sorbent for Pb2+, with a qt value of 246.4 mg g-1 for a 2.0 h equilibrium time. The Pb2+ removal fitted a pseudo-second-order (PSO) model, and the Pb2+ sorption onto Fe2O3@Al2O3 was controlled via a liquid-film diffusion model (LFM), which implied an excellent sorbent–sorbate affinity. The equilibrium studies revealed a better agreement of Pb2+ sorption with the Freundlich isotherm model (FIM), while the thermodynamic results indicated spontaneous endothermic physisorption. Fe2O3@Al2O3 showed an average efficiency of 96.8% in treated seawater (SW) and groundwater (GW) spiked with Pb2+, and the sorbent activity after four cycles was 94.2% of its original efficiency, with an RSD of 5.19.