Electrochemical behaviors of biochar materials during pollutant removal in wastewater: A review

Pivotal water decontamination research has pushed carbon materials thriving and flourishing in recent years. Biochar with merit of electrochemical properties has involved in various redox reactions in water. In this review, electrochemical behaviors (e.g., electron donor, electron acceptor, electron shuttle) of biochar in response to the electrochemical structures (e.g., surface moieties, carbon matrix structures) were systematically compiled as well as the influence from biomass sources and fabrication process including carbonization techniques, pretreatment/modified methods. The impact of solution pH and co-existed substances on the electrochemical behaviors were also included. Furthermore, the approaches that quantitatively determined the electron donating/accepting capacity of biochar were thoroughly analyzed. Finally, some future research prospects are proposed to promote knowledge innovation and underpin practical application. This review aims to provide guidance in taking advantage of electrochemical property of biochar during wastewater purification.