Experimental and theoretical evaluation of synthetized cobalt oxide for phenol adsorption: Adsorption isotherms, kinetics, and thermodynamic studies

Water pollution by phenolic composites is considered a major environmental problem. Therefore, their removal by adsorption is of great practical importance. In this paper, the synthe-sized cobalt oxide Co3O4 was used as an adsorbent for the adsorption of phenol in an aqueous med-ium. A DFT calculation has been carried out to determine the sites accountable for the interactions in phenol molecule, and molecular dynamics (MD) simulations were used to understand the mech-anism of interaction between phenol molecule and Co3O4 surface. The developed adsorbent was characterized by physicochemical methods including XRD, SEM, FT-IR, and BET. The maximum adsorption capacity was observed at pH = 4 with an adsorbed amount of 8.10 mg/g and (R = 98 %). Furthermore, to probe the adsorption action of the phenolic emulsion on the cobalt oxide face, theoretical simulations based on MD (molecular dynamics) and DFT (viscosity func-tional proposal) were performed. The DFT results verified the chemisorption ascendancy while the MD simulations indicated an increased trade of Co3O4 with phenol in the presence of detergent due to water-bridged H-bonds.(c) 2022 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Water pollution caused by phenolic composites is a significant environmental problem, and the use of synthesized cobalt oxide as an adsorbent can effectively remove phenol. A combination of calculations and simulations was used to study the interaction mechanism between phenol molecules and cobalt oxide surface. Experimental characterization results showed that the adsorption capacity was optimal at pH 4.