Effective electro-Fenton-like process for phenol degradation on cerium oxide hollow spheres encapsulated in porous carbon cathode derived from skimmed cotton

Abstract

The uniform size cerium dioxide hollow spheres which were prepared by the SiO₂ hard template method were loaded on microporous porous carbon obtained by carbonization derived from skimmed cotton (CSC) for electro-Fenton-like degradation of phenol. The microstructures of CSC/CeO₂ composite materials were characterized utilizing XRD, BET, XPS, SEM, and TEM. The electrochemical performance of the CSC/CeO₂ cathodes was studied through cyclic voltammetry and electrochemical impedance spectroscopy. The prepared CSC has a hollow tubular structure, and cerium dioxide is evenly loaded on the surface of the CSC in the form of uniform-sized hollow spheres. The CSC/CeO₂ materials have a great specific surface area (287.73 m² g^-1) and a uniform poresize. The electrochemical performance analysis demonstrated that the redox ability of the material greatly was improved by loading CeO₂ on the porous carbon surface of the skimmed cotton. The load ratio of cerium dioxide hollow spheres affects the structure and properties of CSC/CeO₂ materials. Ce³⁺ and Ce⁴⁺ were co-existed in CSC/CeO₂, which promoted the generation of H₂O₂ and ^.OH, and improved the catalytic activity of composite materials. The degradation efficiency of phenol reached 97.6% in 120 min, and the CSC/CeO₂ cathode manifested excellent stability after being experimented 20 times. CSC/CeO₂ composite material has great practical value in the treatment of phenolic wastewater and has promise for further application.

Keywords: Electrocatalytic; Fenton-like catalyst; Hydroxyl radical; Porous carbon.