Gas diffusion electrodes for H2O2 production and their applications for electrochemical degradation of organic pollutants in water: A review.

Nowadays, it is a great challenge to minimize the negative impact of hazardous organic compounds in the environment. Highly efficient hydrogen peroxide (H 2 O 2) production through electrochemical methods with gas diffusion electrodes (GDEs) is greatly demand for degradation of organic pollutants that present in drinking water and industrial wastewater. The GDEs as cathodic electrocatalyst manifest more cost-effective, lower energy consumption and higher oxygen utilization efficiency for H 2 O 2 production as compared to other carbonaceous cathodes due to its worthy chemical and physical characteristics. In recent years, the crucial research and practical application of GDE for degradation of organic pollutants have been well developed. In this review, we focus on the novel design, fundamental aspects, influence factors, and electrochemical properties of GDEs. Furthermore, we investigate the generation of H 2 O 2 through electrocatalytic processes and degradation mechanisms of refractory organic pollutants on GDEs. We describe the advanced methodologies towards electrochemical kinetics, which include the enhancement of GDEs electrochemical catalytic activity and mass transfer process. More importantly, we also highlight the other technologies assisted electrochemical process with GDEs to enlarge the practical application for water treatment. In addition, the developmental prospective and the existing research challenges of GDE-based electrocatalytic materials for real applications in H 2 O 2 production and wastewater treatment are forecasted. According to our best knowledge, only few review articles have discussed GDEs in detail for H 2 O 2 production and their applications for degradation of organic pollutants in water. Unlabelled Image • Efficient GDE cathodes for electrogeneration of H 2 O 2 and water treatment • Fundamentals aspects, influence factors, and electrochemical properties of GDEs are discussed. • Applications of GDEs in electrochemical advanced oxidation processes are described. • The degradation mechanisms of refractory organic pollutants by GDEs are explained. • Research challenges and future perspectives of GDEs are proposed. [ABSTRACT FROM AUTHOR]