Kinetics and Thermodynamics Studies of the Nitrate Reduction Using Zero Valent Iron Nanoparticles Supported on Nanographene

In this manuscript, zero valent iron nanoparticles were synthesized and supported onto high surface area nanographene forming stable ZVINP/NG nanocomposite and used for nitrate catalytic reduction. The effect of nitrate concentration, solution's temperature, and interfering ions on the reduction of nitrate were studied. The catalytic reduction reaction of nitrate by the ZVINP/NG nanocomposite was studied kinetically using different kinetics models, and results showed that the pseudo-second order model converged very well and could describe the reaction with good regression coefficient. On the other hand, the thermodynamics study showed the negative value of Delta G, and positive values of Delta H and Delta S, indicating that the catalytic reduction of nitrate by the ZVINP/NG nanocomposite is product-favored spontaneous reaction, and entropy-driven process. Finally, the applicability of ZVINP/NG nanocomposite for the removal of nitrate was studied using different real samples, and the results showed the great efficiency of the ZVINP/NG nanocomposite for the removal of nitrate ions.