Research status and progress in degradation of organic pollutants via hydrogen evolution reaction and oxygen evolution reaction in wastewater electrochemical treatment

With the development of industry and increase of the world population, environmental pollution has become an important problem facing the world. Among pollutant treatment methods, electrochemical degradation of organic pollutants was a promising but challenging technology for wastewater treatment. Hydrogen evolution reaction and oxygen evolution reaction played important role in the process of pollutant degradation. Anodic oxygen evolution reaction was mainly used to produce living oxygen, •OH or •O2− and other active substances to oxidize and degrade pollutants; Cathodic hydrogen evolution reaction was mainly used to generate H∗ for reduction and dehalogenation. This study summarized and analyzed the mechanism of using hydrogen evolution reaction and oxygen evolution reaction to degrade pollutants. The equipment for degradation of pollutants by hydrogen evolution reaction and oxygen evolution reaction was simple, and the reaction conditions were mild, which could degrade the organics that were difficult to be degraded by common technology. However, the energy consumption was usually high, and toxic intermediates would be produced, which need to be combined with other technologies. Therefore, it was necessary to further explore its mechanism and further improved the efficiency of electrochemical degradation of pollutants.