Bifunctional Catalytic Cooperativity on Nanoedge: Oriented Ce-Fe Bimetallic Fenton Electrocatalysts for Organic Pollutant Control

Electro-Fenton (EF) is one of the promising clean and renewable technologies for organic pollutant control. However, insufficient hydrogen peroxide (H2O2) generation and the subsequent hydroxyl radicals (center dot OH) conversion still prevent the wide applications of EF. Herein, we report a Ce-doped vertically aligned alpha-FeOOH nanoflakes anchored on a carbon felt (CF) cathode for EF operation. In this system, a high concentration H2O2 (113.6 mg/L on 4 cm(2) cathode) is generated in 60 min, and being efficiently catalyzed to center dot OH by virtue of the active nanoedge (1.6 nm thickness) of Ce-doped alpha-FeOOH. The center dot OH production rate is calculated as high as 4.2 mM/W/cm(2) /min, which is similar to 6.6-fold higher compared with the unmodified CF electrode. Moreover, this novel cathode achieves a complete removal (100% removal rate) of ultrahigh concentration chloramphenicol (1.1 mM, 355 mg/L) in 8 h and a high mineralization rate (94%) in 29 h in a scaled-up EF system. Density functional theory calculations (DFT) reveal that the Ce doping in alpha-FeOOH greatly promotes the conversion of H2O2 into center dot OH. This study not only offers a novel cathode structure for EF process but also opens radically new prospects for applied environmental catalysis

Automated summary

Ce-doped vertically aligned alpha-FeOOH nanoflakes anchored on a carbon felt cathode can efficiently generate H2O2 and convert it to center dot OH in Electro-Fenton operation, achieving high removal and mineralization efficiency.