This study shows that it is possible to fabricate and characterize green bimetallic nanoparticles using eco-friendly reduction and a capping agent, which is then used for removing the orange G dye (OG) from an aqueous solution. Characterization techniques such as scanning electron microscopy (SEM), Energy Dispersive Spectroscopy (EDAX), X-Ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) were applied on the resultant bimetallic nanoparticles to ensure the size, and surface area of particles nanoparticles. The results found that the removal efficiency of OG depends on the G‑Fe/Cu‑NPs concentration (0.5-2.0 g.L-1), initial pH (2‑9), OG concentration (10-50 mg.L-1), and temperature (30-50 °C). The batch experiments showed that 54% of 10 mg.L-1 of OG was removed within the optimum dose, pH, and temperature which were 1 g.L-1, 7 and 30°C respectively. The results of kinetic adsorption models and mechanisms indicate that OG uptake on G‑Fe/Cu‑NPs follows the pseudo-second-order kinetic model, physisorption, and exothermic process with (‑22.9 kJ.mol-1) activation energy. Adsorption isotherm investigated with models of Freundlich, Langmuir, Temkin, and Dubinin, in addition, the parameters of thermodynamic such as DG°, DH°, and DS° were ‑0.462 kJ.mol-1, ‑35.88 kJ.mol-1, and 0.116 kJ.mol.K-1 respectively, this indicted spontaneous, exothermic and favorable adsorption.
