Comparative study on Pb2+ adsorption using spinel nanostructures-embedded Graphene Oxide

This study investigates the adsorption performance of spinel nanostructures-embedded grapheneoxide (GO) for removing toxic Pb2+ions from water. The graphene oxide nanocomposites con-taining Fe3O4, CoFe2O4, and NiFe2O4nanoparticles were synthesized and characterized. TheNiFe2O4/GO nanocomposite exhibited the highest Pb2+adsorption capacity, reaching 96.1%removal at 75 minutes contact time with initial Pb2+concentration of 10 ppm. The CoFe2O4/GOnanocomposite achieved 90.3% Pb2+removal under similar conditions, while Fe3O4/GO showed88.8%. Kinetic studies revealed the adsorption followed a pseudo-second-order model with R2values of 0.99-1.00. The adsorption mechanism involves surface adsorption on GO sheets andspinel nanoparticles. The nanocomposites demonstrated good recyclability, maintaining over65% removal efficiency after three consecutive cycles. This study provides insights into design-ing effective adsorbents for mitigating potentially toxic elements pollution in water, addressingenvironmental and public health challenges.