Preparation Of Fe⁰-Fe₃O₄/CeO₂/C Electrode And Its Electrocatalytic Performance

Electro-Fenton technology is considered an effective and promising technology for industrial organic wastewater treatment,and how to improve the electrocatalytic activity of electrode materials in the electrocatalytic process has been a hot research topic of great interest.Biomass porous carbon materials result in the fastest oxygen reduction and maximum accumulation of H₂O₂ due to their porous structure and abundance of active surface sites.CeO₂ can increase the local oxygen concentration near the cathode and accelerate the formation of H₂O₂ and·OH effectively.The reduction efficiency of Fe³⁺to Fe²⁺in the Fenton system depends on the structure of the cathode material and its catalytic ability for the oxygen reduction.Fe⁰ can accelerate the process of Fe³⁺to Fe²⁺reduction in the reaction.In this paper,biomass-derived waste skimmed cotton was used as the carbon source,and skimmed cotton-based porous carbon was prepared by high-temperature carbonization.The cerium dioxide was prepared by the template method and loaded on the porous carbon to prepare CeO₂/C composite materials.The skimmed cotton-based porous carbon had a hollow tubular structure,and cerium dioxide exists in the form of hollow spheres.The CeO₂/C material has a specific surface area of287.73 m² g^-1,and it mainly existed in the form of a microporous structure.The introduction of CeO₂ improves the redox ability of the material,and the coexistence of the two valence states of cerium promotes the generation of hydrogen peroxide and hydroxyl radicals in the system.The electrocatalytic degradation of phenol was established by using CeO₂/C as the cathode and Ti/Tr O₂/Ru O₂ as the anode to find the most suitable conditions for this electrocatalytic degradation system.The phenol removal efficiency of 97.62%was obtained after 120 min of electrocatalysis.The COD was reduced from 238.29 mg L^-1 to 28.28 mg L^-1 after 240 min,and the degradation effect was still excellent after 20 times of reuse.The Fe⁰-Fe₃O₄/CeO₂/C composite cathode was prepared by the impregnation method after ammonia fumigation and the thermal reduction method,and use to degrade ceftriaxone.The introduction of Fe⁰ in the system as a reducing agent effectively accelerated the Fe³⁺/Fe²⁺cycle,allowing the composites to exhibit higher catalytic activity without causing secondary contamination.The synergistic effect of iron and cerium within the catalyst is primarily derived from the acceleration of interfacial electron transfer between Fe³⁺/Fe²⁺and Ce⁴⁺/Ce³⁺in the redox cycle.Electrocatalytic degradation of ceftriaxone sodium was conducted under optimal conditions.The degradation efficiency of 95.59%and the COD removal rate of95.21%were obtained at 120 min and 360 min,respectively.The composite electrode still had a high degradation rate after 25 times of use.