Insights into boosted flow-through electro-Fenton reaction under nanoconfinement

Nanoconfined electro-Fenton system in flow-through configuration holds great potential for water purification, but its optimized design is still hindered by the poor knowledge on the synergisms between electric field and flow field under nanoconfinement. Here, we provided fundamental insights into the structure-performance relations of such systems by combining theoretical calculations, computational fluid dynamics simulations and experimental analyses. In this proof-of-concept study, nanoconfined iron oxide was used as the electrocatalyst to construct the electro-Fenton system for peracetic acid activation and pollutants degradation, while the unconfined counterpart was adopted as a control catalyst. The nanoconfined system exhibited enhanced pollutant oxidation kinetics than the unconfined analog under electric field. In addition, nanoconfinement steered the catalytic pathway from radical to nonradical-dominated reactions, and the flow-through configuration induced convective mass transport to further boost the reaction kinetics. Such a fundamental understanding may lay an important basis for the development of advanced oxidation technologies.