Multifunctional cobalt oxide nanocomposites for efficient removal of heavy metals from aqueous solutions
Abdelaziz El Mouden, Noureddine El Messaoudi, Abdelqader El Guerraf, Amal Bouich, Valbonë Mehmeti, Abdellah Lacherai, Amane Jada, Farooq Sher
Abstract
In this study, co-precipitation synthesis of natural clay (NC) with Co 3 O 4 nanoparticles (NPs) is carried out to elaborate the super NC@Co 3 O 4 nanocomposites with admirable salinity confrontation, environmental stability and reusability, to eliminate heavy metal pollution such as toxic Pb(II) and Cd(II) ions. The advantages of using the NC@Co 3 O 4 adsorbent are easy synthesis and biocompatibility. In addition, NC@Co 3 O 4 can keep an excellent adsorption capacity by taking into account various environmental parameters such as the pH solution, NC@Co 3 O 4 dose, adsorption process time and the initial heavy metals concentration. Furthermore, FTIR, XRD, TGA, SEM-EDS, TEM and AFM analyses were performed to confirm NC@Co 3 O 4 nanocomposites synthesis and characterisation. The adsorption efficiencies of Pb(II) and Cd(II) ions by NC@Co 3 O 4 nanocomposites were demonstrated to be up to 86.89% and 82.06% respectively. Regarding the adsorption from water onto the NC@Co 3 O 4 nanocomposites, kinetics data were well fitted with PSO kinetic model, whereas a good agreement was found between the equilibrium adsorption and theoretical Langmuir isotherm model leading to maximum adsorption capacities of 55.24 and 52.91 mg/g, for Pb(II) and Cd(II) respectively. Monte Carlo (MC) simulations confirmed the spontaneous of this adsorption based on the negative values of E ads . The MC simulations were performed to highlight the interactions occurring between heavy metal ions and the surface of NC@Co 3 O 4 nanocomposites, these were well correlated with the experimental results. Overall the study showed that NC@Co 3 O 4 nanoadsorbents have strongly versatile applications and are well designed for pollutant removal from wastewater due to their unique adsorptive properties.