TY - JOUR
T1 - Carbonaceous cathode materials for electro-Fenton technology
T2 - Mechanism, kinetics, recent advances, opportunities and challenges
AU - Nair, Keerthi M.
AU - Kumaravel, Vignesh
AU - Pillai, Suresh C.
N1 - Publisher Copyright:
© 2020 The Authors
PY - 2021/4
Y1 - 2021/4
N2 - Electro-Fenton (EF) technique has gained significant attention in recent years owing to its high efficiency and environmental compatibility for the degradation of organic pollutants and contaminants of emerging concern (CECs). The efficiency of an EF reaction relies primarily on the formation of hydrogen peroxide (H2O2) via 2e─ oxygen reduction reaction (ORR) and the generation of hydroxyl radicals (●OH). This could be achieved through an efficient cathode material which operates over a wide pH range (pH 3–9). Herein, the current progresses on the advancements of carbonaceous cathode materials for EF reactions are comprehensively reviewed. The insights of various materials such as, activated carbon fibres (ACFs), carbon/graphite felt (CF/GF), carbon nanotubes (CNTs), graphene, carbon aerogels (CAs), ordered mesoporous carbon (OMCs), etc. are discussed inclusively. Transition metals and hetero atoms were used as dopants to enhance the efficiency of homogeneous and heterogeneous EF reactions. Iron-functionalized cathodes widened the working pH window (pH 1–9) and limited the energy consumption. The mechanism, reactor configuration, and kinetic models, are explained. Techno economic analysis of the EF reaction revealed that the anode and the raw materials contributed significantly to the overall cost. It is concluded that most reactions follow pseudo-first order kinetics and rotating cathodes provide the best H2O2 production efficiency in lab scale. The challenges, future prospects and commercialization of EF reaction for wastewater treatment are also discussed.
AB - Electro-Fenton (EF) technique has gained significant attention in recent years owing to its high efficiency and environmental compatibility for the degradation of organic pollutants and contaminants of emerging concern (CECs). The efficiency of an EF reaction relies primarily on the formation of hydrogen peroxide (H2O2) via 2e─ oxygen reduction reaction (ORR) and the generation of hydroxyl radicals (●OH). This could be achieved through an efficient cathode material which operates over a wide pH range (pH 3–9). Herein, the current progresses on the advancements of carbonaceous cathode materials for EF reactions are comprehensively reviewed. The insights of various materials such as, activated carbon fibres (ACFs), carbon/graphite felt (CF/GF), carbon nanotubes (CNTs), graphene, carbon aerogels (CAs), ordered mesoporous carbon (OMCs), etc. are discussed inclusively. Transition metals and hetero atoms were used as dopants to enhance the efficiency of homogeneous and heterogeneous EF reactions. Iron-functionalized cathodes widened the working pH window (pH 1–9) and limited the energy consumption. The mechanism, reactor configuration, and kinetic models, are explained. Techno economic analysis of the EF reaction revealed that the anode and the raw materials contributed significantly to the overall cost. It is concluded that most reactions follow pseudo-first order kinetics and rotating cathodes provide the best H2O2 production efficiency in lab scale. The challenges, future prospects and commercialization of EF reaction for wastewater treatment are also discussed.
KW - AOP
KW - Carbon
KW - Fenton
KW - Kinetic models
KW - Wastewater treatment
KW - Water pollution
UR - http://www.scopus.com/inward/record.url?scp=85098663787&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2020.129325
DO - 10.1016/j.chemosphere.2020.129325
M3 - Review article
C2 - 33385665
AN - SCOPUS:85098663787
SN - 0045-6535
VL - 269
JO - Chemosphere
JF - Chemosphere
M1 - 129325
ER -