Unveiling the Origins of Selective Oxidation in Single-Atom Catalysis via Co–N₄–C Intensified Radical and Nonradical Pathways

Environmental Science & Technology, Год журнала: 2022, Номер 56(16), С. 11635 - 11645

Опубликована: Июль 11, 2022

Single-atom catalysts (SACs)-based peroxymonosulfate (PMS) systems are highly selective to the type of organic pollutants while mechanisms remain ambiguous. In this work, we carried out experimental and theoretical investigations reveal origins selectivity radical nonradical pathways in a designated Co–N4–C/PMS system. Two typical [bisphenol A (BPA) metronidazole (MNZ)] with different molecular structures were employed for comparison. We found that oxidation (SO4•– HO•) electron-transfer pathway (ETP) co-existed Pollutants (e.g., MNZ) high redox potential degraded primarily by free radicals rather than ETP, oxidization low-redox BPA) was dominated ETP at surface region Co–N4–C which overwhelmed contributions homogeneous phase. Intriguingly, could be manipulated PMS loading, simultaneously increased population elevated Co–N4–C-PMS* complexes ETP. Findings from work will unravel mysterious behavior SACs/PMS micropollutants.

Язык: Английский

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Water decontamination via nonradical process by nanoconfined Fenton-like catalysts

Nature Communications, Год журнала: 2023, Номер 14(1)

Опубликована: Май 19, 2023

Abstract There is an urgent need to develop effective and sustainable solutions reduce water pollution. Heterogeneous Fenton-like catalysts are frequently used eliminate contaminants from water. However, the applicability of these limited due low availability reactive species (RS). Herein, nanoconfinement strategy was applied encapsulate short-lived RS at nanoscale boost utilization efficiency in reactions. The nanoconfined catalyst fabricated by assembling Co 3 O 4 nanoparticles carbon nanotube nanochannels achieve exceptional reaction rate excellent selectivity. Experiments collectively suggested that degradation attributed singlet oxygen ( 1 2 ). Density functional theory calculations demonstrated space contributes quantum mutation alters transition state lower activation energy barriers. Simulation results revealed enrichment contaminant on reduced migration distance enhanced . synergy between shell layer core-shell structure further improved selectivity towards oxidation real waters. expected provide a viable for pollution control.

Язык: Английский

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Nitrogen Vacancy-Modulated Peroxymonosulfate Nonradical Activation for Organic Contaminant Removal via High-Valent Cobalt-Oxo Species

Environmental Science & Technology, Год журнала: 2022, Номер 56(9), С. 5611 - 5619

Опубликована: Апрель 20, 2022

Rapid generation of high-valent cobalt-oxo species (Co(IV)═O) for the removal organic contaminants has been challenging because low conversion efficiency Co(III)/Co(II) and high activation energy barrier Co(II)-oxidant complex. Herein, we introduced nitrogen (N) vacancies into graphite carbon nitride imbedded with cobalt carbonate (CCH/CN–Vn) in a peroxymonosulfate (PMS)/visible light system to break limitations conventional two-electron transfer path. These N enhanced electron distribution Co 3d orbital lowered cleave O–O bond PMS Co(II)-PMS complex, achieving modulation major active from 1O2 Co(IV)═O. The developed synergistic that exhibited adsorption oxidation showed remarkable selectivity contaminant performance inorganic (Cl–, NO3–, HCO3–, HPO4–) (HA) even practical aqueous matrices (tap water secondary effluent). This study provides novel mechanistic perspective modulate nonradical path refractory treatment via defect engineering.

Язык: Английский

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MOF Derived Co−Fe nitrogen doped graphite carbon@crosslinked magnetic chitosan Micro−nanoreactor for environmental applications: Synergy enhancement effect of adsorption−PMS activation

Applied Catalysis B Environment and Energy, Год журнала: 2022, Номер 319, С. 121926 - 121926

Опубликована: Сен. 1, 2022

Язык: Английский

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Oxygen doping of cobalt-single-atom coordination enhances peroxymonosulfate activation and high-valent cobalt–oxo species formation

Proceedings of the National Academy of Sciences, Год журнала: 2023, Номер 120(16)

Опубликована: Апрель 11, 2023

The high-valent cobalt-oxo species (Co(IV)=O) is being increasingly investigated for water purification because of its high redox potential, long half-life, and antiinterference properties. However, generation Co(IV)=O inefficient unsustainable. Here, a cobalt-single-atom catalyst with N/O dual coordination was synthesized by O-doping engineering. O-doped (Co-OCN) greatly activated peroxymonosulfate (PMS) achieved pollutant degradation kinetic constant 73.12 min-1 g-2, which 4.9 times higher than that Co-CN (catalyst without O-doping) those most reported single-atom catalytic PMS systems. Co-OCN/PMS realized dominant oxidation pollutants increasing the steady-state concentration (1.03 × 10-10 M) 5.9 compared Co-CN/PMS. A competitive kinetics calculation showed contribution to micropollutant 97.5% during process. Density functional theory calculations influenced charge density (increased Bader transfer from 0.68 0.85 e), optimized electron distribution Co center d-band -1.14 -1.06 eV), enhanced adsorption energy -2.46 -3.03 eV, lowered barrier key reaction intermediate (*O*H2O) formation 1.12 0.98 eV. Co-OCN fabricated on carbon felt flow-through device, continuous efficient removal micropollutants (degradation efficiency >85% after 36 h operation). This study provides new protocol activation elimination through heteroatom-doping metal-oxo purification.

Язык: Английский

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Antibiotics degradation by advanced oxidation process (AOPs): Recent advances in ecotoxicity and antibiotic-resistance genes induction of degradation products

Chemosphere, Год журнала: 2022, Номер 311, С. 136977 - 136977

Опубликована: Окт. 26, 2022

Язык: Английский

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Single-Atom MnN₅ Catalytic Sites Enable Efficient Peroxymonosulfate Activation by Forming Highly Reactive Mn(IV)–Oxo Species

Environmental Science & Technology, Год журнала: 2023, Номер 57(10), С. 4266 - 4275

Опубликована: Фев. 27, 2023

Four-nitrogen-coordinated transitional metal (MN4) configurations in single-atom catalysts (SACs) are broadly recognized as the most efficient active sites peroxymonosulfate (PMS)-based advanced oxidation processes. However, SACs with a coordination number higher than four rarely explored, which represents fundamental missed opportunity for chemistry to boost PMS activation and degradation of recalcitrant organic pollutants. We experimentally theoretically demonstrate here that five-nitrogen-coordinated Mn (MnN5) more effectively activate MnN4 sites, by facilitating cleavage O–O bond into high-valent Mn(IV)–oxo species nearly 100% selectivity. The high activity MnN5 was discerned be due formation higher-spin-state N5Mn(IV)═O species, enable two-electron transfer from organics through lower-energy-barrier pathway. Overall, this work demonstrates importance numbers informs design next-generation environmental catalysts.

Язык: Английский

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Peracetic acid activation via the synergic effect of Co and Fe in CoFe-LDH for efficient degradation of pharmaceuticals in hospital wastewater

Water Research, Год журнала: 2023, Номер 232, С. 119666 - 119666

Опубликована: Янв. 26, 2023

Язык: Английский

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Mechanisms and product toxicity of activated carbon/peracetic acid for degradation of sulfamethoxazole: implications for groundwater remediation

Water Research, Год журнала: 2022, Номер 216, С. 118347 - 118347

Опубликована: Март 24, 2022

Язык: Английский

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Asymmetrically coordinated CoB ₁ N ₃ moieties for selective generation of high‐valent Co‐oxo species via coupled electron‐proton transfer in Fenton‐like reactions

Advanced Materials, Год журнала: 2023, Номер 35(23)

Опубликована: Март 18, 2023

High-valence metal species generated in peroxymonosulfate (PMS)-based Fenton-like processes are promising candidates for selective degradation of contaminants water, the formation which necessitates cleavage OH and OO bonds as well efficient electron transfer. However, high dissociation energy bond makes its quite challenging, largely hampering generation reactive oxygen species. Herein, an asymmetrical configuration characterized by a single cobalt atom coordinated with boron nitrogen (CoB1 N3 ) is established to offer strong local electric field, upon thermodynamically favored via promoted coupled electron-proton transfer process, serves essential step further allow Accordingly, Co(IV)O single-atom Co/PMS system enables highly removal performance toward various organic pollutants. The proposed strategy also holds true other heteroatom doping systems configure asymmetric coordination, thus paving alternative pathways specific conversion rationalized design catalysts at atomic level environmental applications more.

Язык: Английский

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