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 (H 2 O 2 ) generation and the subsequent hydroxyl radicals ( • OH) conversion still prevent the wide applications of EF. Herein, we report a Ce-doped vertically aligned α-FeOOH nanoflakes anchored on a carbon felt (CF) cathode for EF operation. In this system, a high concentration H 2 O 2 (113.6 mg/L on 4 cm 2 cathode) is generated in 60 min, and being efficiently catalyzed to • OH by virtue of the active nanoedge (1.6 nm thickness) of Ce-doped α-FeOOH. The • OH production rate is calculated as high as 4.2 mM/W/cm 2 /min, which is ∼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 α-FeOOH greatly promotes the conversion of H 2 O 2 into • OH. This study not only offers a novel cathode structure for EF process but also opens radically new prospects for applied environmental catalysis.