Generation and transfer of long lifetime reactive oxygen species (ROSs) from electrochemical regulation

Oxygen-containing radicals are a kind of reactive oxygen species (ROSs) and widely used in advanced oxidation processes. ROSs produced by electrochemical process have attracted increasing interest. Both ORR (Oxygen reduction reaction) and WOR (Water oxidation reaction) have been investigated to produce ROSs, while the short lifetime of ROSs limits the oxidation efficiency in application. Hydrogen peroxide (H2O2) can be decomposed to radicals, which is considered as a long-acting ROSs. Despite the ROSs have been extensively studied, much remains to be learned about the electrochemical process enhancement. Developing a deeper understanding of the reaction and mass transfer enhancement will be essential to driving innovation the address grand challenges in high efficiency oxidation in the future. This review will start from the important application of ROSs. After the brief description on the characterization methods of common ROSs, the generation and utilization of ROSs will be discussed. The competitive regulation of 2e- and 4e- reactions for ROSs generation will be mainly illustrated. The mass transfer of ROS as well as efficient decomposition of H2O2 is also highlighted. At end of the review, the outlook for prioritizing strategic research direction will be provided.