Simple modulation of Fe-based single atoms/clusters catalyst with acidic microenvironment for ultrafast Fenton-like reaction

Single atom catalysts (SACs) are emerging as efficient peroxide activators to eliminate water contaminants, yet the correlation between structure and catalytic activity remains elusive. Here we moderated the Fe sites on the carbon nitride and obtained a combination of single atoms and clusters sites on FeCN5 with the recorded methylene blue oxidation rate of 59.43 mg/L min−1 via direct ultrafast H2O2 activation. The excellent performance was mainly ascribed to the high active sites exposure, self-creating acidic microenvironment, and assistance of leaching Fe. Nevertheless, excessive exposure of the catalyst at high pH may destroy the surface environment and inhibit H2O2 activation. To solve this issue, we developed a flow-through filter that reached nearly 100% pollutant degradation and H2O2 utilization and stability over 320 h when treating actual wastewater treatment. These findings provide profound insights into catalyst manipulation at atomic scales and the development of viable catalytic systems toward real-world application.