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

Abstract

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 synthesized 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 BV 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/).;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 synthesized cobalt oxide Co3O4 was used as an adsorbent for the adsorption of phenol in an aqueous medium. 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 mechanism 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 functional 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. © 2022 The Author(s)