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![High-resolution XPS spectra of (A) Co 2p 3/2 , (B) N 1s, (C) Mn 2p 3/2 , and (D) O 1s of Fe 1 Mn 5 Co 4 −N@C before and after reaction. Reaction conditions: [BPA] = 20 mg L −1 , [PMS] = 0.2 g L −1 , catalyst = 0.1 g L −1 , T = 298 K, initial solution pH = 6.0.](profile/Li-Xuning/publication/311561259/figure/fig5/AS:439398958407681@1481772283393/High-resolution-XPS-spectra-of-A-Co-2p-3-2-B-N-1s-C-Mn-2p-3-2-and-D-O-1s-of.png)
High-resolution XPS spectra of (A) Co 2p 3/2 , (B) N 1s, (C) Mn 2p 3/2 , and (D) O 1s of Fe 1 Mn 5 Co 4 −N@C before and after reaction. Reaction conditions: [BPA] = 20 mg L −1 , [PMS] = 0.2 g L −1 , catalyst = 0.1 g L −1 , T = 298 K, initial solution pH = 6.0.
Source publication
![Figure 4. Atomic configuration of PMS on MnO (200) [panel (a)] and Mn 4...](profile/Li-Xuning/publication/311561259/figure/fig4/AS:439398954213387@1481772283015/Atomic-configuration-of-PMS-on-MnO-200-panel-a-and-Mn-4-N-111-surfaces-panel_Q320.jpg)
Innovation in transition metal nitrides (TMNs) preparation is highly desired for realization of various functionalities. Herein, series of graphene encapsulated TMNs (FexMn6-xCo4-N@C) with well-controlled morphology have been synthesized through topotactic transformation of metal-organic frameworks in N2 atmosphere. The as-synthesized FexMn6-xCo4-N...
Contexts in source publication
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... was interesting to see that the weight remained unchanged until the temperature reached 197 °C, suggesting the good stability of the Fe x Mn 6−x Co 4 −N@C nanodices. In addition, considering the large specific surface areas ( Figure S5) and the magnetic separation performance of all four samples, they may have promising potential for sustainable remediation by activation of PMS. ...
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... shown in Table S4, the adsorption on both surface is quite strong with E ads being −4.0 and −5. Figure S14, while negligible changes could be found on the diffraction peaks of FeCo and Mn 4 N. More importantly, the morphology of Fe 1 Mn 5 Co 4 −N@C remained ( Figure S15). All of these results suggest the good stability of the Fe x Mn 6−x Co 4 − N@C nanodices. ...
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... XPS spectra of the used catalyst were applied to further explore the PMS activation mechanism. Figure 5A shows the high-resolution XPS spectra of Co 2p 3/2 of Fe 1 Mn 5 Co 4 −N@C before and after the reaction. Three peaks with binding energy located at 778.5, 780.5, and 782.1 eV could be assigned to the alloyed cobalt (Co 0 ), Co 2+ , and Co 3+ , respectively. ...
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... of these results suggest that the Co 0 and Fe 0 on Fe 1 Mn 5 Co 4 −N@C surface were oxidized during the activation of PMS. The high-resolution XPS spectra of N 1s of the catalyst before and after the reaction are shown in Figure 5B. Negligible changes could be found on the nitrogen bound to the metal (Mn−N and Fe−N) as well as the pyridinic N and graphitic N, indicating the better stability of Mn 4 N for the activation of PMS. ...
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... changes could be found on the nitrogen bound to the metal (Mn−N and Fe−N) as well as the pyridinic N and graphitic N, indicating the better stability of Mn 4 N for the activation of PMS. The XPS spectra of Mn 2p 3/2 ( Figure 5C) could be deconvoluted into three contributions with binding energy located at 639.5, 641.3, and 643.1 eV, attributed to the metallic manganese (Mn 0 ), Mn 2+ , and Mn 3+ , respectively. 8,58 ...
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... relative proportion of Mn 0 was decreased after the reaction, suggesting the partial oxidation of Mn 0 to Mn 2+ and Mn 3+ on the Fe 1 Mn 5 Co 4 −N@C surface. In addition, the increase of the relative proportion of lattice O after reaction (Figure 5d) could further confirm the oxidation of Co 0 , Fe 0 , and Mn 0 during the activation of PMS. However, 12% of the relative contributions of Mn 0 to the overall Mn intensity after reaction further suggest the better stability of Mn 4 N for the activation of PMS. ...
Citations
... However, only a few catalysts can bypass the dissociation of N 2 molecules, thus shifting the determination rate step of the reaction to the formation of N-H bonds [48,138,185]. Here, we introduce a single-atom and single-cluster catalyst that can successfully bypass N 2 molecular cleavage, making the indirect dissociation of *N-NH 2 easier, and the reaction follows a new mechanism, the Eley-Rideal (E-R) mechanism [186,187], N 2 is preferentially hydrogenated to *NNH x (x = 2 or 4, * present the adsorbed state). Liu et al. [95] reported Fe appears as Fe 3 clusters, N 2 is preferentially hydrogenated followed by the formation of NNH 2 and the reaction follows the Eley-Rideal mechanism rather than the conventional Langmuir-Hinshelwood (L-H) mechanism and Mars-van Krevelen mechanism [95,185]. ...
Ammonia is considered a clean energy carrier because of its high hydrogen content, ease of liquefaction, and low carbon emissions. It is mostly manufactured by the Haber-Bosch process. It is critical to the advancement of society and the welfare of people. However, because of the high temperatures and high pressures involved in this process-which uses iron catalysts and fossil fuels to produce hydrogen-it produces greenhouse gasses and requires a lot of energy. Although they struggle with high catalyst prices and low production rates, researchers have looked into alternative ammonia synthesis methods like electrochemical and photochemical ways to overcome this. In order to enable synthesis at lower temperatures and pressures, current efforts are concentrated on creating novel catalysts that will lower reaction conditions. Recent developments in heterogeneous catalysts, including oxides, metal hydrides, oxyhydrides, and electrides, for thermal ammonia synthesis are highlighted in this review. Due to their distinct surface characteristics or electronic structures, these materials have the ability to reduce catalyst poisoning and increase activity while facilitating the breaking of N-N bonds and the storage and release of hydrogen. In order to support the development of effective catalysts for a more sustainable future, we investigate variables influencing catalyst performance and reaction processes. Our goal is to provide guidance for future catalyst design and thermal ammonia synthesis methods.
... Figure 3c,g presents the N1s orbital spectra, where distinct peaks corresponding to different nitrogen configurations are observed. In particular, pyridine N, pyrrolic N, and graphitic N were identified at binding energies of 397.98, 399.79, and 401.62 eV, respectively [43]. These nitrogen configurations, particularly pyridinic, pyrrolic, and graphitic nitrogen, may serve as active sites for PMS activation, as indicated by the literature, and could enhance the performance of the catalyst [40]. ...
Cobalt–nitrogen co-doped carbon nanotubes (Co3@NCNT-800) were synthesized via a facile and economical approach to investigate the efficient degradation of organic pollutants in aqueous environments. This material demonstrated high catalytic efficiency in the degradation of carbamazepine (CBZ) in the presence of peroxymonosulfate (PMS). The experimental data revealed that at a neutral pH of 7 and an initial CBZ concentration of 20 mg/L, the application of Co3@NCNT-800 at 0.2 g/L facilitated a degradation rate of 64.7% within 60 min. Mechanistic investigations indicated that the presence of pyridinic nitrogen and cobalt species enhanced the generation of reactive oxygen species. Radical scavenging assays and electron spin resonance spectroscopy confirmed that radical and nonradical pathways contributed to CBZ degradation, with the nonradical mechanism being predominant. This research presents the development of a novel PMS catalyst, synthesized through an efficient and stable method, which provides a cost-effective solution for the remediation of organic contaminants in water.
... The Co 2p 1/2 and Co 2p 3/2 of DSC@CF ( Figure 4b) were deconvoluted into three sub-peaks, corresponding to Co 3+ (797.6 and 782.1 eV), Co 2+ (796.6 and 780.2 eV), and Co 0 (792.9 and 778 eV) with shake-up satellites (802.6 and 786.2 eV). [30,31] The peaks for Co 3+ and Co 2+ originated from Co 3 O 4 and CoO in the inner shell of DSC, respectively, while those for Co 0 are from the metallic Co core of DSC, as consistent with EELS results (Figure 1). For OCF-DSC@CF, Co 2p 1/2 and Co 2p 3/2 were deconvoluted into two sub-peaks, Co 3+ and Co 2+ , and no peaks cor-responding to Co 0 were detected. ...
Constructing functional materials on a 3D host is an efficient strategy to tackle issues of lithium (Li) metal anodes. Although non‐Li‐alloying materials provide structural stability during cycling due to reduced lattice distortions, low lithiophilicity and sluggish mass transport kinetics limit their functionality. Herein, a synergistic strategy is proposed to improve intrinsic lithiophilicity and mass transport kinetics of non‐Li‐alloying nucleation sites and demonstrate its remarkable efficacy. Two carbon fiber (CF) hosts coated by non‐Li‐alloying nanosheets with and without oxygen‐enriched carbon filler (OCF) as lithiophilicity and mass transport booster (OCF‐DSC@CF and DSC@CF, respectively) are constructed and their physiochemical properties are systematically evaluated to reveal the efficacy of OCF. By advanced characterization techniques, including 3D tomography and location‐dependent electron energy loss spectroscopies, the complex heterostructure of OCF‐DSC@CF with distinctive roles of each constituent is clearly identified. As verified by theoretical and electrochemical analyses, the incorporation of OCF endows OCF‐DSC@CF with substantially improved lithiophilicity and mass transport kinetics. Moreover, OCF‐DSC@CF induces a multifunctional SEI enriched with LiF and LiCx, which exhibits well‐balanced electrical resistivity and ionic conductivity. Benefiting from these attributes, OCF‐DSC@CF exhibits an unprecedented cyclability under a low N/P ratio of 1.8, achieving 700 cycles at 0.5C with an exceptional capacity retention of 97.8%.
... Prussian blue analogues (PBAs), a family of metal-organic frameworks (MOFs) that are assembled by well-aligned metal centers and cyano ligands, have received substantial interest due to their facile synthesis, tunable and versatile structure and composition [23][24][25][26]. Most notably, PBAs have functioned as good sacrificial hosts to derive carbon-encapsulated metallic functional materials, including metal nitrides, sulfides, phosphides and selenides [27][28][29][30]. In these circumstances, the metal atoms in PBAs are easily converted into pony-size metal nanoparticles through the controllable pyrolysis under inert atmosphere, supplying as the precursors for the subsequent fabrication of metallic functional materials. ...
... Peroxymonosulfate (PMS), as a stable and non-toxic oxidant, is usually activated to form SO 4 •− and hydroxyl radical (·OH) [8,9]. Compared with ·OH, SO 4 •− possesses a stronger oxidation potential, broader pH range, and longer half-life [10]. The peroxide O-O bond of PMS could be activated via thermal treatment, ultraviolet irradiation, electrochemistry, and metal or metal-free catalysts [11,12]. ...
Heterogeneous catalysts have been widely used for peroxymonosulfate (PMS) activation to remove persistent contaminants in water. This study successfully prepared cobalt-doped TiO2 using a simple two-step approach for activating PMS to remove tetracycline (TC). The batch experiments showed complete TC degradation within 25 min caused by Co-TiO2 (0.1 g/L) activation of PMS (1 mM) under visible light. The system also demonstrated excellent catalytic efficiency in various water environments, such as artificial seawater, tap water, and wastewater. According to the radical capture tests and electron spin resonance analysis, the contribution of active species involved in the degradation of TC with the Vis/Co-TiO2/PMS system were in the following order: 1O2> SO4•−> O2•−> •OH. The possible TC degradation pathway was proposed using intermediate identification and Fukui function calculation. This study provides a promising method toward organic pollutants degradation and provides a novel perspective on the rational design of competent and stable catalysts.
... V) [12]. In addition, PMS is non-toxic and has a good level of stability [13]. As a result, activated PMS could be expected to show better capacity in degrading the organic contaminants. ...
The abundance of organic pollutants in the aqueous system has posed a serious threat to human health. Here, Co0.5Cu0.5Fe2O4 magnetic nanoparticles (NPs) were successfully synthesized for antibiotic degradation. The properties of the as-prepared photocatalyst were tested by diverse characterization techniques. The effects of the concentration of photocatalyst (20–100 mg L−1) and peroxymonosulfate (PMS) (20–80 mg L−1), and the pH (3–9) of solution on the degradation of tetracycline (TC) in aqueous solution by Co0.5Cu0.5Fe2O4/PMS/light system were investigated comprehensively. The results showed that Co0.5Cu0.5Fe2O4 NPs possessed remarkable photocatalytic performance over a wide pH range with the help of PMS and visible light irradiation. The degradation rate of TC could reach 86.0% at 40 min in the optimized conditions (TC = 10 mg L−1, catalyst = 60 mg L−1, PMS = 60 mg L−1, pH = 7). In addition, the active species quenching experiment demonstrated that h+, SO•4–, and •OH were generated in the degradation progress. Interestingly, h+ served as a conqueror in the reaction system, which benefited from the increased separation capability of electron-hole pairs due to the role of PMS as an electron quencher. Meanwhile, an improved PMS-assisted photocatalytic degradation of the TC reaction mechanism has been presented. Various TC intermediates were also uncovered, and probable degradation pathways were proposed. Furthermore, the Co0.5Cu0.5Fe2O4/PMS/light system was able to degrade a variety of organic pollutants, including naproxen sodium, naproxen, carbamazepine, ofloxacin, and flurbiprofen. The excellent degradation of various organics and high recyclability underline potential applications of Co0.5Cu0.5Fe2O4 NPs.
... Metal-organic frameworks (MOFs), constructed from self-assembly of metal ions/clusters and organic ligands, have been used more significantly in heterogeneous catalysis owing to their unique characteristics of superior specific surface areas and tunable porous structure [13][14][15]. To date, various types of MOF-derived catalysts have been a topic of intense research in SR-AOPs of organic contaminants in wastewater [16][17][18]. In Lei's research team, the cow manure biochar (CMB) loaded cobalt-based MOF (ZIF-67) was used as precursors and then derived at different temperatures, resulting in the Co@NPC-CMB-x biochar-based catalysts. ...
A novel 3D advanced oxidation catalyst ZIF-67@C-CMC/rGO based on carboxymethyl cellulose (CMC) and reduced graphene oxide (rGO) was successfully synthesized by facile in-situ growth of Zeolitic imidazolate framework-67 (ZIF-67). C-CMC/rGO aerogel crosslinked by poly (methyl vinyl ether-alt-maleic acid)/polyethylene glycol system (PMVEMA/PEG) as the host material was prepared through a template-directed growth model and exhibited outstanding mechanical properties. The sustainable composite was successfully used as an efficient catalyst for activating peroxymonosulfate (PMS) to generate SO4-· and ·OH, then leads to the removal of organic contaminants. As a result, almost 100 % of 10 ppm MB/RhB solution can be degraded within 5 min due to the combination of catalyst aerogel and PMS. What's more, the aerogel showed a wide pH tolerance range from 4 to 9 and maintained up to 93 % of the contaminant removal rate compared to the initial value after four cycles. The ZIF-67@C-CMC/rGO aerogel with high load rate and excellent catalytic degradation performance not only solved the problem of dispersion and recovery of ZIF-67 particles, but also provided a new idea for the compound wastewater purification in sulfate radical-based advanced oxidation processes (SR-AOPs).
... Among the transition-metal ions, heterogeneous cobalt-based materials have attracted increasingly considerable concern as more efficient oxidant activators. 20,21 It has been reported that the encapsulated Co nanoparticles optimize the work function through the electron tunneling effect at the metal@carbon interface, reducing the density of states at the Fermi level of the outer graphite layer. 22 The formation of such a heterojunction also enhances the electron transfer ability of the coated carbon to promote the adsorption and dissociation of ozone molecules. ...
... Also, because of the synergistic effect of TM catalysis and the hybrid effect, the reactivity of the PMS/H 2 O 2 activated water oxidation reaction can be significantly improved. 20,21 When forming the TM@carbon heterojunction, the top carbon lattice will provide electrons to TM-NPs through a tightly interacting metal−carbon interface. By increasing the electron density of TM-NPs, reducing its local work function, and increasing the Fermi level, the Fenton-like catalysis is enhanced. ...
... Unique TM@carbon materials with controllable composition, structure, and morphology have been developed using metal−organic framework (MOF) precursors/templates. 20 As another cutting-edge method, the construction of MOF-on-MOF nanostructures, including core−shell MOF@MOF heterostructures, can not only combine the advantages of individual MOF components but also achieve improved structural stability and new capabilities that cannot be obtained directly from MOFs themselves. 26 In this work, a core−shell structured zeolitic imidazolate framework-8@zeolitic imidazolate framework-67 (ZIF-8@ZIF-67) can be obtained through the oriented growth of ZIF-67 [Co(MeIm) 2 ] n on ZIF-8 [Zn(MeIm) 2 ] n crystals, and then, it can be adopted as the sacrificial template to generate the heterostructure of nitrogendoped cobalt@carbon nanotube-grafted carbon (denoted as Co@NCNT/NC) polyhedron. ...
... In contrast, when MCoO@Co-N-C and PMS were present simultaneously, the concentration of BPA started to decrease rapidly and more than 98% of BPA was decomposed in 10 min in which the pseudo-first-kinetics rate constants (k) reached 0.472 min − 1 (Fig. 4b). The k value of MCoO@Co-N-C was higher than that of most previously reported catalysts for the degradation of BPA ( Fig. 4c and Table S2) [44][45][46][47][48][49][50][51][52][53][54][55]. The inappreciable degradation efficiency (nearly 5%) was obtained in the MXene-900/PMS system, which meant that MXene-900 could not decompose BPA. ...
Integrating the merits of the substrate and active sites with the water matrix is of significant importance to design novel catalysts for peroxymonosulfate (PMS)-based advanced oxidation processes. A sandwich-like heterostructure catalyst ([email protected]) were fabricated via anchoring zero-dimensional metal-organic frameworks (MOFs)-derived CoO nanoparticles on two-dimensional Ti3C2Tx MXene nanosheets. Benefiting from the distinctive structure, the resultant catalysts achieved excellent decontamination performance under high salinity conditions (200 mM). Nearly 100% efficiency of bisphenol A (BPA) was degraded within 10 min only using 0.05 g L⁻¹ catalyst and 0.1 g L⁻¹ PMS, with exceptional high turnover frequency (TOF) value (8.64 min⁻¹) which was 22.5 times higher than that of MOFs derived catalysts without MXene. A mediated-electron transfer mechanism is found to be conducive to the oxidation of BPA. This work provides a new approach to novel catalysts designed for removing trace organic contaminants (TrOCs) in saline water.
