In Situ Reconstruction-Directed Electrocatalyst Design Enables Low-Energy Anodic Oxidation for Water Purification

Abstract

Anodic oxidation reactions (AORs) hold promise for degrading persistent organic pollutants, yet practical deployment is constrained by inadequate anode stability and sluggish kinetics under low-bias operation. Prussian blue analogues (PBAs) feature cyanide-bridged metal frameworks with efficient intermetallic electron transfer, yet their surfaces inevitably undergo uncontrolled reconstruction during electrolysis, producing outcomes that range from beneficial activation to detrimental degradation. Here, we reported a first-ever paradigm shift from suppressing reconstruction to actively directing it, demonstrating that the intrinsic instability of FeMn PBA could be harnessed as a design lever. Through an in situ self-reconstruction process, we discovered that the morphology and surface coordination environment were spontaneously reorganized into FeMn nanoflowers grown on carbon paper (FeMn@CP), a configuration never before achieved from this precursor. This reconstruction-guided pathway uniquely yielded a 201-fold increase in electrochemically active surface area (ECSA) over pristine FeMn PBA, alongside markedly enhanced electrochemical stability, synergistic gains not attainable by conventional stabilization strategies. Capitalizing on this reconstructed architecture, FeMn@CP achieved efficient phenolic pollutant degradation at low bias, with robust reusability, broad matrix adaptability, and substantially reduced effluent toxicity. Continuous-flow experiments further verified its sustained performance under practical conditions. This study unveils, for the first time, that catalyst reconstruction, when rationally exploited, serves as a decisive and generalizable strategy to concurrently boost AOR activity and stability, opening an unexplored avenue for designing next-generation electrocatalytic water purification systems.