Foam electrodes for electrochemical wastewater treatment: A review of materials, mechanisms, and applications

Abstract

Foam electrodes, represented by metal foams, are characterized by their highly porous three-dimensional structure and relatively large surface area. They have high electrical conductivity and advanced and promising functional materials in wastewater treatment. The unique design of the structure with porous materials provides increased catalytic sites, improved mass transfer, easier of electron transfer, and long-term durability under extreme operating conditions. These characterizations make them very suitable materials for electrochemical processes. This review focuses on the manufacturing materials of foam electrodes and their new applications in electrochemical oxidation, adsorption, and electrocoagulation processes. It was specifically mentioned various types of electrodes, such as nickel, copper, iron, and aluminum, RVC, graphene and highlights their ability to remove toxic organic contaminants, dyes, and heavy metals .The removal efficiency of the electrochemical processes ranged from 70% to 99% depending on the electrode material .Nickel foam followed by copper then graphene foam had the superior performance in advanced oxidation processes whereas COD removal varied from 40 to 92% depending on the operation conditions . A structured literature survey covering publications from 2015 to 2025 finally, foam electrodes play a significant role in wastewater treatment.