Enhanced degradation of micropollutants over iron-based electro-Fenton catalyst: Cobalt as an electron modulator in mesochannels and mechanism insight

Chen, Xiaoqian; Teng, Wei; Fan, Jianwei; Chen, Yanyan; Ma, Qian; Xue, Yonggang; Zhang, Chuning; Zhang, Wei‐xian

doi:10.1016/j.jhazmat.2021.127896

“…Co 2 p in ECM and FE-ECM was fitted to two same spin–orbit doublets, characteristic peaks of Co 2+ , Co 3+ , and their satellite peaks (Figure S10). However, the peak of Fe 2 p 3/2 assigned to Fe(III) in ECM was around 713.3 eV, and the peak corresponding to Fe(III) was around 713.1 eV in EF-ECM (Figure a) . The negative shift binding energy of Fe 2 p 3/2 in FE-ECM demonstrated the lower valence states and electron-rich structure of Fe(III) after Fe(II) modulation .…”

Section: Resultsmentioning

confidence: 94%

Fe(II)-Modulated Microporous Electrocatalytic Membranes for Organic Microcontaminant Oxidation and Fouling Control: Mechanisms of Regulating Electron Transport toward Enhanced Reactive Oxygen Species Activation

Yang

¹

,

Xu

²

,

Luo

³

et al. 2023

Environ. Sci. Technol.

8

0

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Regulation of the fast electron transport process for the generation and utilization of reactive oxygen species (ROS) by achieving fortified electron "nanofluidics" is effective for electrocatalytic oxidation of organic microcontaminants. However, limited available active sites and sluggish mass transfer impede oxidation efficiency. Herein, we fabricated a conductive electrocatalytic membrane decorated with hierarchical porous vertically aligned Fe(II)-modulated FeCo layered double hydroxide nanosheets (Fe(II)-FeCo LDHs) in an electro-Fenton system to maximize exposure of active sites and expedite mass transfer. The nanospaced interlayers of Fe(II)-FeCo LDHs within the microconfined porous structure formed by its vertical nanosheets highly boost the micro/nanofluidic distribution of target pollutants to active centers/species, achieving accelerated mass transferability. Aliovalent substitution by Fe(II) activates in-plane metallics to maximize the available active sites and makes each Fe(II)-FeCo LDH nanosheet a geometrical nanocarrier for constructing a fast electron "nanofluidic" to accelerate Fe(II) regeneration in Fe(III)/Fe(II) cycles. As a result, the Fe(II)-FeCo LDHs exhibited improved reactivity in catalyzing H 2 O 2 to •OH and 1 O 2 . Accordingly, the membrane exhibited a higher atrazine degradation kinetic (0.0441 min −1 ) and degradation rate (93.2%), which were 4.7 and 2.1 times more than those of the bare carbon nanotube membrane, respectively. Additionally, the enhanced hydrophilic and strongly oxidized reactivity synergistically mitigated the organic fouling occurring in the pores and surface of the membrane. These findings clarify the activation mechanism of ROS over an innovative electrocatalytic membrane reactor design for organic microcontaminant treatment.

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Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H₂O₂ Production and Biomass Upgrading

Xu,

Zhang,

Zhang

et al. 2023

Angewandte Chemie

0

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The integration of highly active single atoms (SAs) and atom clusters (ACs) into an electrocatalyst is critically important for high‐efficiency two‐electron oxygen reduction reaction (2e‐ ORR) to hydrogen peroxide (H2O2). Here we report a tandem impregnation‐pyrolysis‐etching strategy to fabricate the oxygen‐coordinated Fe SAs and ACs anchored on bacterial cellulose derived carbon (BCC) (FeSAs/ACs‐BCC). As the electrocatalyst, FeSAs/ACs‐BCC exhibits superior electrocatalytic activity and selectivity toward 2e‐ ORR, affording an onset potential of 0.78 V (vs. RHE) and a high H2O2 selectivity of 96.5% in 0.1 M KOH. In a flow cell reactor, the FeSAs/ACs‐BCC also achieves high‐efficiency H2O2 production with a yield rate of 12.51 ± 0.18 mol gcat‐1 h‐1 and a faradaic efficiency of 89.4% ± 1.3% at 150 mA cm‐2. Additionally, the feasibility of coupling the produced H2O2 and electro‐Fenton process for the valorization of ethylene glycol was explored in detail. The theoretical calculations uncover that the oxygen‐coordinated Fe SAs effectively regulate the electronic structure of Fe ACs which are the 2e‐ ORR active sites, resulting in the optimal binding strength of *OOH intermediate for high‐efficiency H2O2 production.

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Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H₂O₂ Production and Biomass Upgrading

Xu,

Zhang,

Zhang

et al. 2023

View full text Add to dashboard Cite

The integration of highly active single atoms (SAs) and atom clusters (ACs) into an electrocatalyst is critically important for high‐efficiency two‐electron oxygen reduction reaction (2e‐ ORR) to hydrogen peroxide (H2O2). Here we report a tandem impregnation‐pyrolysis‐etching strategy to fabricate the oxygen‐coordinated Fe SAs and ACs anchored on bacterial cellulose derived carbon (BCC) (FeSAs/ACs‐BCC). As the electrocatalyst, FeSAs/ACs‐BCC exhibits superior electrocatalytic activity and selectivity toward 2e‐ ORR, affording an onset potential of 0.78 V (vs. RHE) and a high H2O2 selectivity of 96.5% in 0.1 M KOH. In a flow cell reactor, the FeSAs/ACs‐BCC also achieves high‐efficiency H2O2 production with a yield rate of 12.51 ± 0.18 mol gcat‐1 h‐1 and a faradaic efficiency of 89.4% ± 1.3% at 150 mA cm‐2. Additionally, the feasibility of coupling the produced H2O2 and electro‐Fenton process for the valorization of ethylene glycol was explored in detail. The theoretical calculations uncover that the oxygen‐coordinated Fe SAs effectively regulate the electronic structure of Fe ACs which are the 2e‐ ORR active sites, resulting in the optimal binding strength of *OOH intermediate for high‐efficiency H2O2 production.

show abstract

Enhanced degradation of micropollutants over iron-based electro-Fenton catalyst: Cobalt as an electron modulator in mesochannels and mechanism insight

Cited by 23 publications

References 50 publications

Fe(II)-Modulated Microporous Electrocatalytic Membranes for Organic Microcontaminant Oxidation and Fouling Control: Mechanisms of Regulating Electron Transport toward Enhanced Reactive Oxygen Species Activation

Fe(II)-Modulated Microporous Electrocatalytic Membranes for Organic Microcontaminant Oxidation and Fouling Control: Mechanisms of Regulating Electron Transport toward Enhanced Reactive Oxygen Species Activation

Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H₂O₂ Production and Biomass Upgrading

Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H₂O₂ Production and Biomass Upgrading

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Enhanced degradation of micropollutants over iron-based electro-Fenton catalyst: Cobalt as an electron modulator in mesochannels and mechanism insight

Cited by 23 publications

References 50 publications

Fe(II)-Modulated Microporous Electrocatalytic Membranes for Organic Microcontaminant Oxidation and Fouling Control: Mechanisms of Regulating Electron Transport toward Enhanced Reactive Oxygen Species Activation

Fe(II)-Modulated Microporous Electrocatalytic Membranes for Organic Microcontaminant Oxidation and Fouling Control: Mechanisms of Regulating Electron Transport toward Enhanced Reactive Oxygen Species Activation

Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H2O2 Production and Biomass Upgrading

Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H2O2 Production and Biomass Upgrading

Contact Info

Product

Resources

About

Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H₂O₂ Production and Biomass Upgrading

Atomically Dispersed Iron Regulating Electronic Structure of Iron Atom Clusters for Electrocatalytic H₂O₂ Production and Biomass Upgrading