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1.
Nature ; 606(7915): 706-712, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35732759

RESUMO

To use natural gas as a feedstock alternative to coal and oil, its main constituent, methane, needs to be isolated with high purity1. In particular, nitrogen dilutes the heating value of natural gas and is, therefore, of prime importance for removal2. However, the inertness of nitrogen and its similarities to methane in terms of kinetic size, polarizability and boiling point pose particular challenges for the development of energy-efficient nitrogen-removing processes3. Here we report a mixed-linker metal-organic framework (MOF) membrane based on fumarate (fum) and mesaconate (mes) linkers, Zr-fum67-mes33-fcu-MOF, with a pore aperture shape specific for effective nitrogen removal from natural gas. The deliberate introduction of asymmetry in the parent trefoil-shaped pore aperture induces a shape irregularity, blocking the transport of tetrahedral methane while allowing linear nitrogen to permeate. Zr-fum67-mes33-fcu-MOF membranes exhibit record-high nitrogen/methane selectivity and nitrogen permeance under practical pressures up to 50 bar, removing both carbon dioxide and nitrogen from natural gas. Techno-economic analysis shows that our membranes offer the potential to reduce methane purification costs by about 66% for nitrogen rejection and about 73% for simultaneous removal of carbon dioxide and nitrogen, relative to cryogenic distillation and amine-based carbon dioxide capture.

2.
J Am Chem Soc ; 146(43): 29943-29954, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39418115

RESUMO

The development of green and efficient hydrogen peroxide (H2O2) production is of great interest but remains challenging. Herein, we develop a new and simple strategy via locking the coplanarity in highly crystalline covalent triazine frameworks (CTFs) to remarkably boost direct photosynthesis of H2O2 from oxygen and water. The exfoliated ultrathin 2D-CTF nanosheets exhibit excellent photocatalytic H2O2 evolution with an ultrahigh solar-to-chemical efficiency of 0.91% and a superb apparent quantum yield of 16.8% at 420 nm, surpassing all previous CTFs and most of the metal-free photocatalysts ever reported. Our detailed experimental and theoretical studies reveal that the spatially locked structure in the crystalline CTF photocatalyst can not only greatly enhance the separation and transfer of photoexcited charge-carriers for promoting H2O2 photogeneration but also alter the local electronic structures that unexpectedly turn water oxidation from a four-electron route to a two-electron pathway, resulting in a 100% atom utilization efficiency. This work provides valuable insights into the designed synthesis of highly efficient metal-free photocatalysts and precise control over photocatalytic reaction pathways in organic materials.

3.
Small ; 20(14): e2307116, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37988688

RESUMO

Iron trifluoride (FeF3) is attracting tremendous interest due to its lower cost and the possibility to enable higher energy density in lithium-ion batteries. However, its cycle performance deteriorates rapidly in less than 50 cycles at elevated temperatures due to cracking of the unstable cathode solid electrolyte interface (CEI) followed by active materials dissolution in liquid electrolyte. Herein, by engineering the salt composition, the Fe3O4-type CEI with the doping of boron (B) atoms in a polymer electrolyte at 60 °C is successfully stabilized. The cycle life of the well-designed FeF3-based composite cathode exceeds an unprecedented 1000 cycles and utilizes up to 70% of its theoretical capacities. Advanced electron microscopy combined with density functional theory (DFT) calculations reveal that the B in lithium salt migrates into the cathode and promotes the formation of an elastic and mechanic robust boron-contained CEI (BOR-CEI) during cycling, by which the durability of the CEI to frequent cyclic large volume changes is significantly enhanced. To this end, the notorious active materials dissolution is largely prohibited, resulting in a superior cycle life. The results suggest that engineering the CEI such as tuning its composition is a viable approach to achieving FeF3 cathode-based batteries with enhanced performance.

4.
Small ; : e2405649, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39263810

RESUMO

Nitric oxide (NO), a key element in the regulation of essential biological mechanisms, presents huge potential as therapeutic agent in the treatment and prevention of chronic diseases. Metal-organic frameworks (MOFs) with open metal sites are promising carriers for NO therapies but delivering it over an extended period in biological media remains a great challenge due to i) a fast degradation of the material in body fluids and/or ii) a rapid replacement of NO by water molecules onto the Lewis acid sites. Here, a new ultra-narrow pores Fe bisphosphonate MOF, denoted MIP-210(Fe) or Fe(H2O)(Hmbpa) (H4mbpa = p-xylenediphosphonic acid) is described that adsorbs NO due to an unprecedented sorption mechanism: coordination of NO through the Fe(III) sites is unusually preferred, replacing bound water, and creating a stable interaction with the free H2O and P-OH groups delimiting the ultra-narrow pores. This, associated with the high chemical stability of the MOF in body fluids, enables an unprecedented slow replacement of NO by water molecules in biological media, achieving an extraordinarily extended NO delivery time over at least 70 h, exceeding by far the NO kinetics release reported with others porous materials, paving the way for the development of safe and successful gas therapies.

5.
Phys Rev Lett ; 133(16): 166701, 2024 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-39485963

RESUMO

Two-dimensional (2D) altermagnetism was recently proposed to be attainable in twisted antiferromagnetic bilayers providing an experimentally feasible approach to realize it in 2D materials. Nevertheless, a comprehensive understanding of the mechanism governing the appearance of altermagnetism in bilayer systems is still absent. In the present Letter, we address this gap by introducing a general stacking theory (GST) as a key condition for the emergence of altermagnetism in bilayer systems. The GST provides straightforward criteria to predict whether a bilayer demonstrates altermagnetic spin splitting, solely based on the layer groups of the composing monolayers. According to the GST, only seven point groups of bilayers facilitate the emergence of altermagnetism. It is revealed that, beyond the previously proposed antiferromagnetic twisted Van der Waals stacking, altermagnetism can even emerge in bilayers formed through the symmetrically restricted direct stacking of two monolayers. By combining the GST and first-principles calculations, we present illustrative examples of bilayers demonstrating altermagnetism. Our work establishes a robust framework for designing diverse bilayer systems with altermagnetism, thereby opening up new avenues for both fundamental research and practical applications in this field.

6.
Angew Chem Int Ed Engl ; 63(32): e202407298, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38777794

RESUMO

Crystalline porous framework materials have attracted tremendous interest in electrocatalytic CO2 reduction owing to their ordered structures and high specific surface areas as well as rich designability, however, still suffer from a lack of accuracy in regulating the binding strength between the catalytic sites and intermediates, which is crucial for optimizing the electrocatalytic activity and expanding the product types. Herein, we report three new kinds of vinylene-linked metal-covalent organic frameworks (TMT-CH3-MCOF, TMP-CH3-MCOF and TMP-MCOF) with continuously tunable D-π-A interactions by adjusting the structure of the monomers at the molecular level for realizing efficient electroreduction of CO2 to formate for the first time. Interestingly, compared with TMT-CH3-MCOF and TMP-MCOF, the TMP-CH3-MCOF exhibited the highest HCOO- Faradaic efficiency (FEHCOO-) of 95.6 % at -1.0 V vs RHE and displayed the FEHCOO- above 90 % at the voltage range of -1.0 to -1.2 V vs. RHE, which is one of the highest among various kinds of reported electrocatalysts. Theoretical calculations further reveal that the catalytic sites in TMP-CH3-MCOF with unique moderate D-π-A interactions have suitable binding ability towards the reaction intermediate, which is beneficial for the formation of *HCOO and desorption of *HCOOH, thus effectively promoting the electroreduction of CO2 to formate.

7.
Angew Chem Int Ed Engl ; 63(6): e202317664, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38131249

RESUMO

Crystalline covalent triazine frameworks (CTFs) have gained considerable interest in energy and catalysis owing to their well-defined nitrogen-rich π-conjugated porosity and superior physicochemical properties, however, suffer from very limited molecular structures. Herein we report a novel solvent-free FeCl3 -catalyzed polymerization of 2, 6-pyridinedicarbonitrile (DCP) to achieve the first synthesis of crystalline, dual-porous, pyridine-based CTF (Fe-CTF). The FeCl3 could not only act as a highly active Lewis acid catalyst for promoting the two-dimensional ordered polymerization of DCP monomers, but also in situ coordinate with the tridentate chelators generated between pyridine and triazine groups to yield unique Fe-N3 single-atom active sites in Fe-CTF. Abundant few-layer crystalline nanosheets (Fe-CTF NSs) could be prepared through simple ball-milling exfoliation of the bulk layered Fe-CTF and exhibited remarkable electrocatalytic performance for oxygen reduction reaction (ORR) with a half-wave potential and onset potential up to 0.902 and 1.02 V respectively, and extraordinary Zn-air battery performance with an ultrahigh specific capacity and power density of 811 mAh g-1 and 230 mW cm-2 respectively. By combining operando X-ray absorption spectroscopy with density functional theory calculations, we revealed a dynamic and reversible evolution of Fe-N3 to Fe-N2 during the electrocatalytic process, which could further accelerate the electrocatalytic reaction.

8.
J Am Chem Soc ; 145(23): 12745-12754, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37171112

RESUMO

Scalable and eco-friendly synthesis of crystalline two-dimensional (2D) polymers with proper band gap and single-layer thickness is highly desired for the fundamental research and practical applications of 2D polymers; however, it remains a considerable and unresolved challenge. Herein, we report a convenient and robust method to synthesize a series of crystalline covalent triazine framework nanosheets (CTF NSs) with a thickness of ∼80 nm via a new solvent-free salt-catalyzed nitrile cyclotrimerization process, which enables the cost-effective large-scale preparation of crystalline CTF NSs at the hundred-gram level. Theoretical calculations and detailed experiments revealed for the first time that the conventional salts such as KCl can not only act as physical templates as traditionally believed but also more importantly can efficiently catalyze the cyclotrimerization reaction of carbonitrile monomers as a new kind of green solid catalysts to achieve crystalline CTF NSs. Upon simple liquid-phase sonication, these CTF NSs can be easily further exfoliated into abundant single-layer crystalline 2D triazine polymers (2D-TPs) in high yields. The obtained atomically thin crystalline 2D-TPs with a band gap of 2.36 eV and rich triazine active groups exhibited a remarkable photocatalytic hydrogen evolution rate of 1321 µmol h-1 under visible light irradiation with an apparent quantum yield up to 29.5% at 420 nm and excellent photocatalytic overall water splitting activity with a solar-to-hydrogen efficiency up to 0.35%, which exceed all molecular framework materials and are among the best metal-free photocatalysts ever reported. Moreover, the processable 2D-TPs could be readily assembled on a support as a photocatalytic film device, which demonstrated superior photocatalytic performance (135.2 mmol h-1 m-2 for hydrogen evolution).

9.
Int J Mol Sci ; 24(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36834775

RESUMO

Metal-organic frameworks (MOFs) attract growing interest in biomedical applications. Among thousands of MOF structures, the mesoporous iron(III) carboxylate MIL-100(Fe) (MIL stands for the Materials of Lavoisier Institute) is among the most studied MOF nanocarrier, owing to its high porosity, biodegradability, and lack of toxicity. Nanosized MIL-100(Fe) particles (nanoMOFs) readily coordinate with drugs leading to unprecedented payloads and controlled release. Here, we show how the functional groups of the challenging anticancer drug prednisolone influence their interactions with the nanoMOFs and their release in various media. Molecular modeling enabled predicting the strength of interactions between prednisolone-bearing or not phosphate or sulfate moieties (PP and PS, respectively) and the oxo-trimer of MIL-100(Fe) as well as understanding the pore filling of MIL-100(Fe). Noticeably, PP showed the strongest interactions (drug loading up to 30 wt %, encapsulation efficiency > 98%) and slowed down the nanoMOFs' degradation in simulated body fluid. This drug was shown to bind to the iron Lewis acid sites and was not displaced by other ions in the suspension media. On the contrary, PS was entrapped with lower efficiencies and was easily displaced by phosphates in the release media. Noticeably, the nanoMOFs maintained their size and faceted structures after drug loading and even after degradation in blood or serum after losing almost the totality of the constitutive trimesate ligands. Scanning electron microscopy with high annular dark field (STEM-HAADF) in conjunction with X-Ray energy-dispersive spectrometry (XEDS) was a powerful tool enabling the unraveling of the main elements to gain insights on the MOF structural evolution after drug loading and/or upon degradation.


Assuntos
Antineoplásicos , Estruturas Metalorgânicas , Ferro/química , Estruturas Metalorgânicas/química , Prednisolona
10.
Angew Chem Int Ed Engl ; 61(48): e202210857, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36165854

RESUMO

Uncommon reversible guest-induced metal-hemilabile linker bond dynamics in MOF MFM-300(Sc) was unraveled to switch on/switch off catalytic open metal sites. The catalytic activity of this MOF with non-permanent open metal sites was demonstrated using a model Strecker hydrocyanation reaction as a proof-of-concept. Conclusively, the catalytic activity was evidenced to be fully reversible, preserving the conversion performance and structure integrity of MFM-300(Sc) over multiple cycles. These experimental findings were corroborated by quantum-calculations that revealed a reaction mechanism driven by the Sc-open metal sites. This discovery paves the way towards the design of new effective and easily regenerable heterogeneous MOF catalysts integrating switchable metal sites.

11.
Inorg Chem ; 58(15): 9655-9662, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31310522

RESUMO

Mössbauerite, a trivalent iron-only layered oxyhydroxide, has been recently identified as an electrocatalyst for water oxidation. We investigated the material as potential cocatalyst for photoelectrochemical water oxidation on semiconductor photoanodes. The band edge positions of mössbauerite were determined for the first time with a combination of Mott-Schottky analysis and UV-vis diffuse reflectance spectroscopy. The positive value of the Mott-Schottky slope and the flatband potential of 0.34 V vs reversible hydrogen electrode (RHE) identifies the material as an n-type semiconductor, but bare mössbauerite does not produce noticeable photocurrent during water oxidation. Type-II heterojunction formation by facile drop-casting with WO3 thin films yielded photoanodes with amended charge carrier separation and photocurrents up to 1.22 mA cm-2 at 1.23 V vs RHE. Mössbauerite is capable of increasing the charge carrier separation at lower potential and improving the photocurrent during photoelectrochemical water oxidation. The rise in photocurrent of the mössbauerite-functionalized WO3 photoanode thus originates from improved charge carrier separation and augmented hole collection efficiency. Our results highlight the potential of mössbauerite as a second-phase catalyst for semiconductor electrodes.

12.
Nanotechnology ; 30(32): 325402, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-30965295

RESUMO

Layered double hydroxide with exchangeable interlayer anions are considered promising electro-active materials for renewable energy technologies. However, the limited exposure of active sites and poor electrical conductivity of hydroxide powder restrict its application. Herein, bifunctional integrated electrode with a 3D hierarchical carbon framework decorated by nickel iron-layered double hydroxides (NiFe-LDH) is developed. A conductive carbon nanowire array is introduced not only to provide enough anchoring sites for the hydroxide, but also affords a continuous pathway for electron transport throughout the entire electrode. The 3D integrated architecture of NiFe-hydroxide and hierarchical carbon framework possesses several beneficial effects including large electrochemical active surfaces, fast electron/mass transport, and enhanced mechanical stability. The as-prepared electrode affords a current density of 10 mA cm-2 at a low overpotential of 269 mV for oxygen evolution reaction (OER) in 1 M of KOH. It also offers excellent stability with negligible current decline even after 2000 cycles. Besides, density functional theory calculations revealed that the (110) surface of NiFe-LDH is more active than the (003) surface for OER. Furthermore, the electrode possesses promising application prospects in alkaline battery-supercapacitor hybrid devices with a capacity of 178.8 mAh g-1 (capacitance of 1609.6 F g-1) at a current density of 0.2 A g-1. The viability of the as-prepared bifunctional electrode will provide a potential solution for wearable electronics in the near future.

13.
Small ; 14(48): e1803344, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30345625

RESUMO

As a popular strategy, interlayer expansion significantly improves the Li-ion diffusion kinetics in the MoS2 host, while the large interlayer spacing weakens the van der Waals force between MoS2 monolayers, thus harming its structural stability. Here, an oxygen-incorporated MoS2 (O-MoS2 )/graphene composite as a self-supported intercalation host of Li-ion is prepared. The composite delivers a specific capacity of 80 mAh g-1 in only 36 s at a mass loading of 1 mg cm-2 , and it can be cycled 3000 times (over 91% capacity retention) with a 5 mg cm-2 loading at 2 A g-1 . The O-MoS2 exhibits a dominant 1T phase with an expanded layer spacing of 10.15 Å, leading to better Li-ion intercalation kinetics compared with pristine MoS2 . Furthermore, ex situ X-ray diffraction tests indicate that O-MoS2 sustains a stable structure in cycling compared with the gradual collapse of pristine MoS2 , which suffers from excessive lattice breathing. Density functional theory calculations suggest that the MoOx (OH)y pillars in O-MoS2 interlayers not only expand the layer spacing, but also tense the MoS2 layers to avoid exfoliation in cycling. Therefore, the O-MoS2 shows a pseudolayered structure, leading to remarkable durability besides the outstanding rate capability as a Li-ion intercalation host.

14.
Chemistry ; 24(46): 11916-11921, 2018 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30024068

RESUMO

Light-driven water splitting is a potential source of abundant, clean energy, yet efficient charge-separation and size and position of the bandgap in heterogeneous photocatalysts are challenging to predict and design. Synthetic attempts to tune the bandgap of polymer photocatalysts classically rely on variations of the sizes of their π-conjugated domains. However, only donor-acceptor dyads hold the key to prevent undesired electron-hole recombination within the catalyst via efficient charge separation. Building on our previous success in incorporating electron-donating, sulphur-containing linkers and electron-withdrawing, triazine (C3 N3 ) units into porous polymers, we report the synthesis of six visible-light-active, triazine-based polymers with a high heteroatom-content of S and N that photocatalytically generate H2 from water: up to 915 µmol h-1 g-1 with Pt co-catalyst, and-as one of the highest to-date reported values -200 µmol h-1 g-1 without. The highly modular Sonogashira-Hagihara cross-coupling reaction we employ, enables a systematic study of mixed (S, N, C) and (N, C)-only polymer systems. Our results highlight that photocatalytic water-splitting does not only require an ideal optical bandgap of ≈2.2 eV, but that the choice of donor-acceptor motifs profoundly impacts charge-transfer and catalytic activity.

15.
Nanoscale ; 16(7): 3438-3447, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38265127

RESUMO

Two-dimensional (2D) metal-organic frameworks (MOFs) hold immense potential for various applications due to their distinctive intrinsic properties compared to their 3D analogues. Herein, we designed a highly stable NiF2(pyrazine)2 2D MOF in silico with a two-dimensional periodic wine-rack architecture. Extensive first-principles calculations and molecular dynamics (MD) simulations based on a newly developed machine learning potential (MLP) revealed that this 2D MOF exhibits huge in-plane Poisson's ratio anisotropy. This results in anomalous negative in-plane stretchability, as evidenced by an uncommon decrease in its in-plane area upon the application of uniaxial tensile strain, which makes this 2D MOF particularly attractive for flexible wearable electronics and ultra-thin sensor applications. We further demonstrated the unique capability of MLP to accurately predict the finite-temperature properties of MOFs on a large scale, exemplified by MLP-MD simulations with a dimension of 28.2 × 28.2 nm2, relevant to the length scale experimentally attainable for the fabrication of MOF films.

16.
Nanoscale ; 16(21): 10340-10349, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38738992

RESUMO

The A2B+B'3+X6-type lead-free halide perovskite Cs2NaInCl6 has demonstrated limited luminescence performance attributed to parity-forbidden transitions in its intrinsic form. While extensive exploration has been dedicated to partial cation substitution in Cs2NaInCl6, there is a noticeable gap in understanding the impact of anion composition on this material. In this study, we investigated the influence of anion composition on the luminescence performance of Cs2NaInX6 using first-principles calculations. We first conducted calculations on Cs2NaInX6 in its intrinsic state and on Cs2NaInCl6 with cation substitution to establish the reliability of the transition dipole moment (TDM) as a luminescence descriptor in this system. Following this, we systematically assessed the formation energies, octahedral distortions, and luminescence properties of Cs2NaInX6 with diverse anion compositions. Despite sharing similar stability, closely aligned with the experimentally accessible Cs2NaInCl6, all mixed halide structures exhibited significant octahedral distortions. Additionally, most of these structures displayed considerably enhanced TDM compared to their single halide counterparts. Notably, the structures Cs2NaInX4X'2-b and Cs2NaInX3X'3-b demonstrated superior luminescence performance compared to other structures. The absorption spectra calculated for selected structures revealed the enhancement of their photo-absorbance in the presence of iodine, particularly in the low energy region. This observation provides additional evidence that light absorbance in different energy regions can be effectively regulated in this way. Finally, we also investigated other optical properties that impact luminescence performances, such as the energy loss spectrum L(ω), the reflectivity spectrum R(ω) and the refractivity index n(ω). The findings offer insights into optimizing the luminescence performance of lead-free halide perovskites through anion composition variation.

17.
Nat Commun ; 15(1): 9456, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39487110

RESUMO

Indoor air pollution is one of the major threads in developed countries, notably due to high concentrations of formaldehyde, a harmful molecule difficult to eliminate. Addressing this purification challenge while adhering to the principles of sustainable development requires the use of innovative, advanced sustainable materials. Here we show that by combining state-of-the-art spectroscopic techniques with density-functional theory molecular simulations, we have developed an advantageous mild chemisorption synergistic mechanism using porous metal (III or IV) pyrazole- di-carboxylate based metal-organic framework (MOF) to trap formaldehyde in a reversible manner, without incurring significant energy penalties for regeneration. A straightforward, environmentally friendly, and scalable synthesis protocol was established for the porous, water-stable aluminum pyrazole dicarboxylate known as Al-3.5-PDA or MOF-303, capable of functioning as a highly efficient and reusable filter. It demonstrates selectivity and high storage capacity for formaldehyde under conditions typical of severe indoor use, such as in housing or vehicle cockpits, including varying VOC mixtures and concentrations, humidity, and temperature, without any accidental release. Furthermore, we have successfully regenerated this sorbent using a simple domestic protocol, ensuring the material reusability for at least 10 cycles.

18.
ACS Nano ; 18(27): 17483-17491, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38913669

RESUMO

The development of highly selective and energy efficient technologies for electrochemical CO2 reduction combined with renewable energy sources holds great promise for advancing the field of sustainable chemistry. The engineering of copper-based electrodes facilitates the conversion of CO2 into high-value multicarbon products (C2+). However, the ambiguous determination of the intrinsic CO2 activity and the maximization of the density of exposed active sites have severely limited the use of Cu for the realization of practical electrocatalytic devices. Here, we report a scalable strategy to obtain a high density of undercoordinated sites by maximizing the exposure of grain-boundary active sites using a direct chronoamperometric pulse method. Our numerical investigations predicted that grain boundaries modulate the adsorption behavior of *CO on the Cu surface, which acts as a key intermediate species associated with the production of multicarbon species. We investigated the consequence of grain-boundary density on dendric Cu catalysts (GB-Cu) by combining transmission electron microscopy, in situ Raman spectroscopy, and X-ray photoelectron spectroscopy with electrochemical measurements. A linear relationship between the Faradaic efficiency of the C2+ product and the presence of undercoordinated sites was observed, which allowed to directly quantify the contribution of the grain boundary in Cu-based catalysts on the CO2RR properties and the formation of multicarbon products. Using a membrane electrode assembly electrolyzer, the high grain-boundary density Cu electrodes achieved a maximum Faradaic efficiency of 73.2% for C2+ product formation and a full-cell energy efficiency of 20.2% at a specific current density of 303.6 mA cm-2. The GB-Cu was implemented in a 25 cm2 MEA electrolyzer and demonstrated selectivity of over 62% for 70 h together with current retention of 88.4% at the applied potential of -3.80 V. The catalysts and electrolyzer were further coupled to an InGaP/GaAs/Ge triple-junction solar cell to demonstrate a solar-to-fuel (STF) conversion efficiency of 8.33%. This work designed an undercoordinated Cu-based catalyst for the realization of solar-driven fuel production.

19.
J Colloid Interface Sci ; 679(Pt A): 824-833, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39395221

RESUMO

Iron, one of the most abundant elements on earth and an essential element for living organisms, plays a crucial role in our daily metabolism. In the field of catalysis, the development of high-performance catalysts based on less toxic iron element is also of significant importance for green chemistry and a sustainable future. To construct Fe-based heterogeneous catalysts with excellent hydrogenation performance, precise modulation of the atomic coordination structure is a key strategy for enhancing catalytic activity. In this study, we present an in-situ coating method for applying a zeolitic imidazolate framework (ZIF) onto the surface of fungal hyphae. The asymmetric coordination structure of Fe1-N3P1 was precisely tailored by utilizing the phosphorus source from the fungus and the nitrogen source in the ZIFs. Detailed characterizations and density functional theory calculations revealed that the incorporation of ZIFs not only increased the specific surface area of catalysts, but also facilitated the dispersion of Fe2P nanoparticles into the Fe1-N3P1 center, making the lowest reaction energy barrier and resulting in the best performance for nitrobenzene hydrogenation when compared to the Fe2P nanoparticles and clusters. This research introduces a novel design concept for constructing asymmetric monoatomic configuration based on the inherent characteristics of natural microorganisms and the exogenous porous coordination polymers.

20.
Nanomicro Lett ; 16(1): 78, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38190094

RESUMO

The concentration difference in the near-surface region of lithium metal is the main cause of lithium dendrite growth. Resolving this issue will be key to achieving high-performance lithium metal batteries (LMBs). Herein, we construct a lithium nitrate (LiNO3)-implanted electroactive ß phase polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) crystalline polymorph layer (PHL). The electronegatively charged polymer chains attain lithium ions on the surface to form lithium-ion charged channels. These channels act as reservoirs to sustainably release Li ions to recompense the ionic flux of electrolytes, decreasing the growth of lithium dendrites. The stretched molecular channels can also accelerate the transport of Li ions. The combined effects enable a high Coulombic efficiency of 97.0% for 250 cycles in lithium (Li)||copper (Cu) cell and a stable symmetric plating/stripping behavior over 2000 h at 3 mA cm-2 with ultrahigh Li utilization of 50%. Furthermore, the full cell coupled with PHL-Cu@Li anode and LiFePO4 cathode exhibits long-term cycle stability with high-capacity retention of 95.9% after 900 cycles. Impressively, the full cell paired with LiNi0.87Co0.1Mn0.03O2 maintains a discharge capacity of 170.0 mAh g-1 with a capacity retention of 84.3% after 100 cycles even under harsh condition of ultralow N/P ratio of 0.83. This facile strategy will widen the potential application of LiNO3 in ester-based electrolyte for practical high-voltage LMBs.

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