Ultrahigh Peroxymonosulfate Utilization Efficiency over CuO Nanosheets via Heterogeneous Cu(III) Formation and Preferential Electron Transfer during Degradation of Phenols

Environmental Science & Technology, Год журнала: 2022, Номер 56(12), С. 8984 - 8992

Опубликована: Май 31, 2022

In persulfate activation by copper-based catalysts, high-valent copper (Cu(III)) is an overlooked reactive intermediate that contributes to efficient utilization and organic pollutant removal. However, the mechanisms underlying heterogeneous enhanced are not fully understood. Here, oxide (CuO) nanosheets (synthesized with a facile precipitation method) exhibited high catalytic activity for peroxymonosulfate (PMS) 100% 4-chlorophenol (4-CP) degradation within 3 min. Evidence critical role of surface-associated Cu(III) on PMS 4-CP over wide pH range (pH 3-10) was obtained using in situ Raman spectroscopy, electron paramagnetic resonance, quenching tests. directly oxidized other phenolic pollutants, rate constants inversely proportional their ionization potentials. preferentially oxidizes rather than react two molecules generate one molecule 1O2, thus minimizing this less pathway. Accordingly, much higher efficiency (77% electrons accepted ascribed mineralization) CuO/PMS radical pathway-dominated Co3O4/PMS system (27%) or 1O2 α-MnO2/PMS (26%). Overall, these results highlight potential benefits via oxidation offer mechanistic insight into ultrahigh

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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A critical review on correlating active sites, oxidative species and degradation routes with persulfate-based antibiotics oxidation

Water Research, Год журнала: 2023, Номер 235, С. 119926 - 119926

Опубликована: Март 27, 2023

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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CoN₁O₂ Single‐Atom Catalyst for Efficient Peroxymonosulfate Activation and Selective Cobalt(IV)=O Generation

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(27)

Опубликована: Апрель 26, 2023

High-valent metal-oxo (HVMO) species are powerful non-radical reactive that enhance advanced oxidation processes (AOPs) due to their long half-lives and high selectivity towards recalcitrant water pollutants with electron-donating groups. However, high-valent cobalt-oxo (CoIV =O) generation is challenging in peroxymonosulfate (PMS)-based AOPs because the 3d-orbital occupancy of cobalt would disfavor its binding a terminal oxygen ligand. Herein, we propose strategy construct isolated Co sites unique N1 O2 coordination on Mn3 O4 surface. The asymmetric configuration able accept electrons from 3d-orbital, resulting significant electronic delocalization at for promoted PMS adsorption, dissociation subsequent CoIV =O species. CoN1 /Mn3 exhibits intrinsic activity activation sulfamethoxazole (SMX) degradation, highly outperforming counterpart CoO3 configuration, carbon-based single-atom catalysts CoN4 commercial oxides. effectively oxidize target contaminants via atom transfer produce low-toxicity intermediates. These findings could advance mechanistic understanding molecular level guide rational design efficient environmental catalysts.

Язык: Английский

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Fe-Mn oxycarbide anchored on N-doped carbon for enhanced Fenton-like catalysis: Importance of high-valent metal-oxo species and singlet oxygen

Applied Catalysis B Environment and Energy, Год журнала: 2023, Номер 340, С. 123204 - 123204

Опубликована: Авг. 22, 2023

Язык: Английский

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Generation of Fe^IV=O and its Contribution to Fenton‐Like Reactions on a Single‐Atom Iron−N−C Catalyst

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(10)

Опубликована: Янв. 10, 2023

Generating FeIV =O on single-atom catalysts by Fenton-like reaction has been established for water treatment; however, the generation pathway and oxidation behavior remain obscure. Employing an Fe-N-C catalyst with a typical Fe-N4 moiety to activate peroxymonosulfate (PMS), we demonstrate that generating is mediated Fe-N-C-PMS* complex-a well-recognized nonradical species induction of electron-transfer oxidation-and determined adjacent Fe sites specific Fe1 -Fe1 distance are required. After atoms <4 Å PMS-saturated, formed 4-5 can coordinate FeII -N4 , forming inter-complex enhanced charge transfer produce =O. enables system efficiently oxidize various pollutants in substrate-specific, pH-tolerant, sustainable manner, where its prominent contribution manifests higher one-electron potential.

Язык: Английский

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Reducing agents enhanced Fenton-like oxidation (Fe(III)/Peroxydisulfate): Substrate specific reactivity of reactive oxygen species

Water Research, Год журнала: 2022, Номер 218, С. 118412 - 118412

Опубликована: Апрель 6, 2022

Язык: Английский

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Calcination temperature regulates non-radical pathways of peroxymonosulfate activation via carbon catalysts doped by iron and nitrogen

Chemical Engineering Journal, Год журнала: 2022, Номер 451, С. 138468 - 138468

Опубликована: Авг. 4, 2022

Язык: Английский

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Do We Appropriately Detect and Understand Singlet Oxygen Possibly Generated in Advanced Oxidation Processes by Electron Paramagnetic Resonance Spectroscopy?

Environmental Science & Technology, Год журнала: 2023, Номер 57(25), С. 9394 - 9404

Опубликована: Июнь 13, 2023

Electron paramagnetic resonance (EPR) spectroscopy using sterically hindered amine is extensively applied to detect singlet oxygen (1O2) possibly generated in advanced oxidation processes. However, EPR-detectable 1O2 signals were observed not only the 1O2-dominated hydrogen peroxide (H2O2)/hypochlorite (NaClO) reaction but surprisingly also 1O2-absent Fe(II)/H2O2, UV/H2O2, and ferrate [Fe(VI)] process with even stronger intensities. By taking advantage of characteristic between 9,10-diphenyl-anthracene near-infrared phosphorescent emission 1O2, was excluded Fe(VI) process. The false detection ascribed direct piperidyl radical by reactive species [e.g., •OH Fe(VI)/Fe(V)/Fe(IV)] via transfer, followed molecular addition (forming a piperidylperoxyl radical) back generate nitroxide radical, as evidenced successful identification intermediate at 100 K theoretical calculations. Moreover, compared highly oxidative (e.g., high-valence Fe), much lower reactivity profound nonradiative relaxation H2O resulted it too selective inefficient organic contaminant destruction. This study demonstrated that EPR-based could be remarkably misled common thereby jeopardize understandings on 1O2.

Язык: Английский

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