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Electro-reduction of O2to generate H2O2is an attractive alternative to the current anthraquinone process and quite necessary for chemical industries and environmental remediation. In general, sufficient porous structure contributes to expose more catalytic active sites and shorten diffusion paths for the heterogeneous catalysis of O2. In this work, initially the Fe3O4nanoparticles embedded graphite felt (Fe3O4@GF) is prepared through a mild hydrothermal following with thermal reduction method. This special combination not only provides iron source for the electro-Fenton reaction but also supplies rich active sites from the Fe3O4embedded structure with abundant cracks, which are beneficial to increase the reaction rate. Compared with raw graphite felt (RGF), fresh Fe3O4@GF exhibits superior pollutant degradation kinetics with more than 400% increase and approximately 37.8% improvement to the removal of total organic carbon. A 98% decolorization of rhodamine B (RhB) can be achieved in just 5 min and quickly completes 100% removal of RhB in the next few seconds. As the electro-Fenton reaction progresses, Fe3O4dissolves in the electrolyte, leaving a porous structure on the surface of the GF to form a porous GF (PGF), and the rapid radical reaction activates the GF surface. Both the chemical etching of Fe3O4and the electro-Fenton process can further increase the specific surface area, defects, and actives sites of the electrode. As expected, the active PGF exhibits favorable performance of H2O2production in electrolytes of different pHs: 1 (320.0 ± 36.5 mg L–1), 3 (301.9 ± 13.2 mg L–1), and 7 (320.4 ± 21.2 mg L–1). The degradation performance of PGF does not significantly decay even after 20 cycles of repeated use, indicating the good structural stability and long-term durability. The superiority of the in situ Fe source and fast reaction kinetics for electro-Fenton of Fe3O4@GF is confirmed, and this holey engineered strategy also provides the possibility to achieve swift water purification and open up a new way for developing efficient carbon-based electrodes.