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1.
Small ; 20(31): e2311505, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38433398

ABSTRACT

The rational design of heterogeneous catalysts is crucial for achieving optimal physicochemical properties and high electrochemical activity. However, the development of new amorphous-crystalline heterostructures is significantly more challenging than that of the existing crystalline-crystalline heterostructures. To overcome these issues, a coordination-assisted strategy that can help fabricate an amorphous NiO/crystalline NiCeOx (a-NiO/c-NiCeOx) heterostructure is reported herein. The coordination geometry of the organic ligands plays a pivotal role in permitting the formation of coordination polymers with high Ni contents. This consequently provides an opportunity for enabling the supersaturation of Ni in the NiCeOx structure during annealing, leading to the endogenous spillover of Ni from the depths of NiCeOx to its surface. The resulting heterostructure, featuring strongly coupled amorphous NiO and crystalline NiCeOx, exhibits harmonious interactions in addition to low overpotentials and high catalytic stability in the oxygen evolution reaction (OER). Theoretical calculations prove that the amorphous-crystalline interfaces facilitate charge transfer, which plays a critical role in regulating the local electron density of the Ni sites, thereby promoting the adsorption of oxygen-based intermediates on the Ni sites and lowering the dissociation-related energy barriers. Overall, this study underscores the potential of coordinating different metal ions at the molecular level to advance amorphous-crystalline heterostructure design.

2.
Small ; : e2402255, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38837847

ABSTRACT

The application of electrically conductive 1D coordination polymers (1D CPs) in nanoelectronic molecular recognition is theoretically promising yet rarely explored due to the challenges in their synthesis and optimization of electrical properties. In this regard, two tetrathiafulvalene-based 1D CPs, namely [Co(m-H2TTFTB)(DMF)2(H2O)]n (Co-m-TTFTB), and {[Ni(m-H2TTFTB)(CH3CH2OH)1.5(H2O)1.5]·(H2O)0.5}n (Ni-m-TTFTB) are successfully constructed. The shorter S···S contacts between the [M(solvent)3(m-H2TTFTB)]n chains contribute to a significant improvement in their electrical conductivities. The powder X-ray diffraction (PXRD) under different organic solvents reveals the flexible and dynamic structural characteristic of M-m-TTFTB, which, combined with the 1D morphology, lead to their excellent performance for sensitive detection of volatile organic compounds. Co-m-TTFTB achieves a limit of detection for ethanol vapor down to 0.5 ppm, which is superior to the state-of-the-art chemiresistive sensors based on metal-organic frameworks or organic polymers at room temperature. In situ diffuse reflectance infrared Fourier transform spectroscopy, PXRD measurements and density functional theory calculations reveal the molecular insertion sensing mechanism and the corresponding structure-function relationship. This work expands the applicable scenario of 1D CPs and opens a new realm of 1D CP-based nanoelectronic sensors for highly sensitive room temperature gas detection.

3.
Small ; : e2400941, 2024 Mar 26.
Article in English | MEDLINE | ID: mdl-38529737

ABSTRACT

Multidimensional metabolic analysis has become a new trend in establishing efficient disease monitoring systems, as the constraints associated with relying solely on a single dimension in refined monitoring are increasingly pronounced. Here, coordination polymers are employed as derivative precursors to create multishell hollow hybrids, developing an integrated metabolic monitoring system. Briefly, metabolic fingerprints are extracted from hundreds of serum samples and urine samples, encompassing not only membranous nephropathy but also related diseases, using high-throughput mass spectrometry. With optimized algorithm and initial feature selection, the established combined panel demonstrates enhanced accuracy in both subtype differentiation (over 98.1%) and prognostic monitoring (over 95.6%), even during double blind test. This surpasses the serum biomarker panel (≈90.7% for subtyping, ≈89.7% for prognosis) and urine biomarker panel (≈94.4% for subtyping, ≈76.5% for prognosis). Moreover, after attempting to further refine the marker panel, the blind test maintains equal sensitivity, specificity, and accuracy, showcasing a comprehensive improvement over the single-fluid approach. This underscores the remarkable effectiveness and superiority of the integrated strategy in discriminating between MN and other groups. This work has the potential to significantly advance diagnostic medicine, leading to the establishment of more effective strategies for patient management.

4.
Small ; : e2400348, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38564790

ABSTRACT

Production of green hydrogen (H2) is a sustainable process able to address the current energy crisis without contributing to long-term greenhouse gas emissions. Many Ag-based catalysts have shown promise for light-driven H2 generation, however, pure Ag-in its bulk or nanostructured forms-suffers from slow electron transfer kinetics and unfavorable Ag─H bond strength. It is demonstrated that the complexation of Ag with various chalcogenides can be used as a tool to optimize these parameters and reach improved photocatalytic performance. In this work, metal-organic-chalcogenolate assemblies (MOCHAs) are introduced as effective catalysts for light-driven hydrogen evolution reaction (HER) and investigate their performance and structural stability by examining a series of AgXPh (X = S, Se, and Te) compounds. Two catalyst-support sensitization strategies are explored: by designing MOCHA/TiO2 composites and by employing a common Ru-based photosensitizer. It is demonstrated that the heterogeneous approach yields stable HER performance but involves a catalyst transformation at the initial stage of the photocatalytic process. In contrast to this, the visible-light-driven MOCHA-dye dyad shows similar HER activity while also ensuring the structural integrity of the MOCHAs. The work shows the potential of MOCHAs in constructing photosystems for catalytic H2 production and provides a direct comparison between known AgXPh compounds.

5.
Small ; 20(30): e2311057, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38385809

ABSTRACT

Low-cost and eco-friendly Ni/NiO heterojunctions have been theoretically proven to be the ideal candidate for stepwise electrocatalysis of alkaline hydrogen evolution reaction, attributed to the preferred OHad adsorption by incompletely filled d orbitals of NiO phase and favorable Had adsorption energy of Ni phase. Nevertheless, most Ni/NiO compounds reported so far fail to exhibit excellent catalytic activity, possibly due to the lack of efficient electron transport, limited interfacial active sites, and unregulated Nin+ ratios. To address the above bottlenecks, herein, the ultrasmall Ni/NiOx@C nanocapsules (<5 nm) are directly constructed by graphitization of four-layer Ni-based coordination polymers at record low temperatures of 400 °C. Ascribed to the accelerated electron and mass transfer by the carbon nano-onions coated around Ni/NiOx heterojunctions, the extreme rise in interfaces and Ni3+ defects with t6 2ge1 g electronic configuration owed to the ultrasmall size, the Ni/NiOx@C nanocapsules exhibit the highest catalytic activity and the lowest overpotential of η10 = 80 mV among various Ni/NiO materials (measured on the glassy carbon electrode). This work not only constructs an industrialized high-efficiency electrocatalyst toward alkaline HER, but also provides a novel strategy for the constant-scale preparation of multicomponent transition metals-based nanocrystals below 4 nm.

6.
Chemistry ; 30(4): e202302887, 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-37906679

ABSTRACT

Cooling [Fe(bbtr)3 ](BF4 )2 (bbtr=1,4-di(1,2,3-triazol-1-yl)butane) triggers very slow spin crossover below 80 K (T1/2 ↓ =76 K). The spin crossover (SCO) is accompanied by a hysteresis loop (T1/2 ↑ =89 K). In contrast to isostructural perchlorate analogue [Fe(bbtr)3 ](ClO4 )2 in which spin crossover during cooling is preceded by phase transition at TPT =126 K in tetrafluoroborate phase transition does not occur to the beginning of spin crossover (80 K). Studies of mixed crystals [Fe(bbtr)3 ](BF4 )2(1-x) (ClO4 )2x (0.5≤x≤0.9) showed that a phase transition precedes spin crossover, however, for x≅0.46 intersection of T1/2 (x) and TPT (x) dependencies takes place. The application of pressure of 1 GPa shifts the spin crossover in [Fe(bbtr)3 ](BF4 )2 to a temperature above 270 K. High-pressure studies of neat tetrafluoroborate and perchlorate, as well as mixed crystals [Fe(bbtr)3 ](BF4 )2(1-x) (ClO4 )2x (0.1≤x≤0.9), revealed that at 295 K P1/2 value changes linearly with x indicating similar mechanism of spin crossover under elevated pressure in all systems under investigation. Variable pressure single crystal X-ray diffraction studies confirmed that in contrast to thermally induced spin crossover undergoing differently in tetrafluoroborate and perchlorate an application of high pressure removes this differentiation leading to a similar mechanism depending at first on start spin crossover and then P-3→P-1 phase transition occurs. In this report we have shown that 2D coordination polymer [Fe(bbtr)3 ](BF4 )2 (bbtr=1,4-di(1,2,3-triazol-1-yl)butane) treated to date as spin crossover silent shows thermally induced spin crossover phenomenon. Spin crossover in tetrafluoroborate is extremely slow. Determination of the spin crossover curve required carrying measurement in the settle mode-cooling from 85 to 70 K took about 600 h (average velocity of change of temperature ca. 0.0004 K/min).

7.
Chemistry ; 30(31): e202400962, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38538537

ABSTRACT

Cost-effective and facile synthetic routes to organic ligands, along with porous materials that exhibit exceptional gas-storage properties, promise significant industrial applications. Here, a two-step synthesis of novel organophosphorus ligands without metal catalysts is reported. These ligands serve as versatile linkers for the construction of metal-organic frameworks (MOFs) incorporating various metal ions, including zinc and copper. One of the zinc-based MOFs demonstrates remarkable gas-storage properties, with a hydrogen (H2) capacity exceeding 2.5 wt% at 77 K and 100 kPa as well as a carbon dioxide (CO2) capacity exceeding 20 wt% at 298 K and 100 kPa. Furthermore, this zinc-based MOF can be synthesized through a solvothermal process on the gram scale that yields high-quality single crystals.

8.
Chemistry ; 30(40): e202401464, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38738456

ABSTRACT

Bispidine based Hg(II) coordination polymers of helical topology CP-MeOH and CP-EtOH are almost isostructural (they mainly differ for the solvent included in their lattice and by a small % in unit cell parameters) but they differ for everything else: i) their intrinsic stability, ii) their ability to adsorb solvents upon prior evacuation, iii) their accessible structural transformations. In particular, one of the two starting materials, once evacuated, is capable to adsorb methanol from atmospheres containing binary and ternary mixtures of volatile organic compounds (MeOH, CHCl3 and EtOH) under ambient conditions (25 °C, 1 atm) and with a marked selectivity. The other one is not, but undergoes a 1D to 2D dimensionality change which can be monitored in situ by SC-XRD through a SC-to-SC process.

9.
Mol Pharm ; 21(2): 781-790, 2024 Feb 05.
Article in English | MEDLINE | ID: mdl-38153044

ABSTRACT

There is an urgent need to develop efficient treatments for highly invasive triple-negative breast cancer (TNBC) with a high rate of postoperative. Baicalin (BA) has shown inhibitory effects on several tumor cells and could activate ferroptosis in some tumor cells by producing reactive oxygen species (ROS). For overcoming the shortcomings of BA in clinical applications and enhancing the effect of ferroptosis in TNBC, herein, a multifunctional liposome (BA-Fe(III) coordination-polymer-loaded liposome, BA-Fe(III) Lipo) was developed for synergistic chemotherapy of TNBC with ferroptosis activation. Fe(III) released from BA-Fe(III) Lipo could be efficiently reduced to Fe(II) in the presence of high glutathione in tumor microenvironment, which in turn catalyzed the oxidation of unsaturated fats through lipid peroxidation for more ROS production. In addition, BA-Fe(III) Lipo activated tumor cell ferroptosis by down-regulating the enzymatic activity of ferritin heavy chain 1 protein and glutathione peroxidase. This study provided a novel therapeutic strategy for the treatment of TNBC by ingeniously combining chemotherapy with the activation of ferroptosis, which presented potential clinical applications.


Subject(s)
Ferroptosis , Triple Negative Breast Neoplasms , Humans , Triple Negative Breast Neoplasms/drug therapy , Liposomes , Ferric Compounds , Reactive Oxygen Species , Glutathione , Cell Line, Tumor , Tumor Microenvironment
10.
Mol Pharm ; 21(3): 1015-1026, 2024 Mar 04.
Article in English | MEDLINE | ID: mdl-38288698

ABSTRACT

Vaccines have historically faced challenges regarding stability, especially in regions lacking a robust cold chain infrastructure. This review delves into established and emergent techniques to improve the thermostability of vaccines. We discuss the widely practiced lyophilization method, effectively transforming liquid vaccine formulations into a solid powdered state, enhancing storage and transportation ability. However, potential protein denaturation during lyophilization necessitates alternative stabilization methods. Cryoprotectants, namely, starch and sugar molecules, have shown promise in protecting vaccine antigens and adjuvants from denaturation and augmenting the stability of biologics during freeze-drying. Biomineralization, a less studied yet innovative approach, utilizes inorganic or organic-inorganic hybrids to encapsulate biological components of vaccines with a particular emphasis on metal-organic coordination polymers. Encapsulation in organic matrices to form particles or microneedles have also been studied in the context of vaccine thermostability, showing some ability to store outside the cold-chain. Unfortunately, few of these techniques have advanced to clinical trials that evaluate differences in storage conditions. Nonetheless, early trials suggest that alternative storage techniques are viable and emphasize the need for more comprehensive studies. This review underscores the pressing need for heat-stable vaccines, especially in light of the increasing global distribution challenges. Combining traditional methods with novel approaches holds promise for the future adaptability of vaccine distribution and use.


Subject(s)
Hot Temperature , Vaccines , Humans , Drug Stability , Drug Compounding/methods , Vaccination , Freeze Drying/methods
11.
J Fluoresc ; 2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38625573

ABSTRACT

By employing a mixed-ligand strategy, we synthesized two new coordination polymers (CPs) featuring Co(II): {Co(H2L)(bib)]·2H2O}n (1) and {Co(L)(bib)2]·2H2O}n (2), where H4L represents 5-(3,5-dicarboxybenzyloxy) isophthalic acid, and bib denotes 1,4-bis(1-imidazolyl)benzene. These CPs were obtained through the reaction of H4L, a flexible carboxylic acid ligand, with Co(NO3)2·6H2O in various solvent mixtures, along with the N-donor co-ligand bib. Complexes 1 and 2 are formed through distinct coordination modes, resulting in their distinct structural features and excellent fluorescent properties. Based on ligand-centered fluorescence emission and the blue shift (CP 1) along with red shift (CP 2) characteristics, both complexes show promise for applications in fields such as blue fluorescence sensing materials and luminescent materials. After successfully synthesizing two CPs, CP 1 was chosen as the carrier for loading temozolomide (TMZ). Subsequently, leveraging the unique advantages of hydrogels, we developed a novel metal gel formulation loaded with TMZ. The inhibitory effect of this formulation on the growth of glioblastoma was evaluated. Our results demonstrate a significant suppression of glioblastoma cell proliferation by this system, providing an effective avenue for glioblastoma treatment.

12.
J Fluoresc ; 2024 May 28.
Article in English | MEDLINE | ID: mdl-38805133

ABSTRACT

The development of luminescent coordination polymers for the selective sensing of Pb2+ in water constitutes an active area of research that impacts analytical, environmental, and inorganic chemistry. Herein, two novel water-stable 2D Zn-coordination polymers {[Zn2(H2O)2(tdc)2(bpy)]·(H2O)}n 1 and [Zn(tdc)(tmb)]n 2 (tdc = thiophenedicarboxylate; bpy = 4,4'-bipyridine and tmb = 4,4'-trimethylenebipyridine) were synthesized, structurally determined by single crystal X-ray diffraction, and studied in-depth as luminescent sensors for a series of cations (Ca2+, Mg2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+ Cd2+, Hg2+ and Pb2+) in 20% aqueous ethanol. These Zn-polymers possess photostability in 20% aqueous ethanol with a strong emission at 410 upon excitation at 330 nm and quantum yields of around Φ = 0.09. Under these conditions, Pb+2 can be efficiently sensed with polymer 2 through a fluorescent ratiometric response with selectivity over common interfering metal ions such as Cu2+, Cd2+ and Hg2+ in the micromolar concentration range (detection limit = 1.78 ± 10 µM). Such selectivity/affinity of Pb2+ over Hg2+ for luminescent chemosensors is still rare. On the basis of spectroscopic tools (1H NMR, far ATR-IR, PXRD), the X-ray crystal structure of 2, and Scanning Electron Microscopy with Energy-Dispersive X-ray Spectroscopic analysis, the ratiometric fluorescent response is proposed via an efficient metal-ion exchange driven through interactions between thiophenedicarboxylate rings and Pb2+ ions. The use of flexible luminescent Zn-coordination polymers as sensors for selective and direct detection of Pb2+ in aqueous media has been unexplored until now.

13.
J Fluoresc ; 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38483693

ABSTRACT

Design and fabrication of integrated multifunctional probes with intrinsic catalytic and detection abilities is of great importance to simplify the operation in biosensing application with high sensitivity. Herein, dual-emitting lanthanide coordination polymers (Ln-CPs) were facilely prepared by self-assembly of guanine diphosphate (GDP), terephthalic acid (TA), Tb3+ and Cu2+ designated as Tb/Cu-GDP/TA CPs. The doped Cu2+ endowed CPs with obviously enhanced peroxidase mimicking activity compared with free Cu2+. In the presence of H2O2, the probe catalyzed the oxidation of TA generating a new blue fluorescent product, while the fluorescence of Tb3+ decreased simultaneously. Therefore, a new sensitive ratiometric fluorescent sensor for H2O2 has been developed with a good linear range from 0.01 to 300 µM and limit of 1.62 nM. Moreover, the proposed platform could be extended to GSH ratiometric assay in the presence of H2O2, and interestingly, the detection performance could be easily adjusted by adding different concentration of H2O2. This work will facilitate the development of luminescent nanoenzymes based on Ln-CPs to construct the simple ratiomatric sensing platform.

14.
Luminescence ; 39(1): e4601, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37743791

ABSTRACT

A new class of lanthanide mixed-carboxylate ligands compounds with formula {[Ln2 (phthgly)4 (bdc)(H2 O)6 ]·(H2 O)4 }∞ , labelled as Ln3+ : Eu (1) and Gd (2) coordination polymers (CP) were synthesized under mild reaction conditions between lanthanide nitrate salts and a solution of N-phthaloylglycine (phthgly) and terephthalic (bdc) ligands. The (1) and (2) coordination polymers were formed by symmetric binuclear units, in which phthgly and bdc carboxylate ligands are coordinated to the lanthanide ions by different coordination modes. Surprisingly, all organic ligands participate in hydrogen bonding interactions, forming an extremally rigid crystalline structure. The red narrow emission bands from the 5 D0 →7 FJ transitions of the Eu3+ ion show a high colour purity. The intramolecular energy transfer process from L→Eu3+ ion has been discussed. The experimental intensity parameters (Ω2,4 ) reflect lower angular distortion and polarizability of the chemical environment around the metal ion compared with other Eu3+ compounds reported in the literature. This novel class of coordination polymer offers a more attractive platform for developing luminescent functional materials for different applications.


Subject(s)
Lanthanoid Series Elements , Organometallic Compounds , Phthalic Acids , Lanthanoid Series Elements/chemistry , Organometallic Compounds/chemistry , Polymers/chemistry , Models, Molecular , Crystallography, X-Ray , Ligands , Carboxylic Acids
15.
Mikrochim Acta ; 191(6): 317, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38724862

ABSTRACT

A simple, sensitive dual-emission probe was developed for the detection of phosphate (Pi). The probe Tb-BTB/DPA was synthesized by mixing dual-ligand, 1,3,5-tri(4-carboxyphenyl) benzene (H3BTB) and dipicolinic acid (DPA), with metal ions Tb3+ in ethanol-water solution at 40℃ for 2 h. Tb-BTB/DPA exhibits two emission peaks, the emission at 362 nm is attributed to H3BTB, an energy transfer between Tb3+ nodes, and DPA further enhances the fluorescence of Tb3+ at 544 nm. Pi competes with ligand H3BTB to coordinate Tb3+, resulting in partial collapse of the Tb-BTB/DPA structure and interrupting the electron transfer between H3BTB and Tb3+. Therefore, the emission at 362 nm is enhanced, while the emission at 544 nm is unchanged, and a ratiometric fluorescence method is developed to detect Pi. Tb-BTB/DPA exhibits good linearity within the Pi concentration range (0.1-50 µmol/L), and the detection limit was 25.8 nmol/L. This study provides a new way to prepare probes with dual emission sensing properties.

16.
Molecules ; 29(14)2024 Jul 22.
Article in English | MEDLINE | ID: mdl-39065015

ABSTRACT

Seven new lanthanide coordination polymers, namely [Ln(cpt)3H2O)]n(Ln = La (1), Pr (2), Sm (3), Eu (4), Gd (5), Dy (6), and Er (7)), which were synthesized under hydrothermal conditions using 4'-(4-(4-carboxyphenyloxy)phenyl)-4,2':6',4'-tripyridine (Hcpt) as the ligand. The crystal structures of these seven complexes were determined using single-crystal X-ray diffraction, and they were found to be isostructural, crystallizing in the triclinic P1- space group. The Ln(III) ions were nine-coordinated with tricapped trigonal prism coordination geometry. The Ln(III) cations were coordinated by carboxylic and pyridine groups from (cpt)- ligands, forming one-dimensional ring-chain structures. Furthermore, the luminescent properties of complexes 1-7 were investigated using fluorescent spectra in the solid state. The fluorescence sensing experiments demonstrated that complex 4 exhibits high selectivity and sensitivity for detecting Co2+, Cu2+ ions, and nitrobenzene. Moreover, complex 3 shows good capability for detecting Cu2+ ions and nitrobenzene. Additionally, the sensing mechanism was also thoroughly examined through theoretical calculations.

17.
Molecules ; 29(9)2024 May 03.
Article in English | MEDLINE | ID: mdl-38731615

ABSTRACT

Interaction of the pre-organized complex of iron(II) trimethylacetate and 1,10-phenanthroline (phen) [Fe2(piv)4(phen)2] (1) (piv = (Me)3CCO2-)) with 1,6-diaminohexane (dahx) in anhydrous acetonitrile yielded a 1D coordination polymer [Fe3O(piv)6(dahx)1.5]n (2) and an organic salt of pivalic acid (H2dahx)(piv)2 (3). The structure of the obtained compounds was determined by single-crystal X-ray diffraction analysis. The phase purity of the complexes was determined by powder X-ray diffraction analysis. According to the single-crystal X-ray analysis, coordination polymer 2 is formed due to the binding of a triangular carboxylate core {Fe3(µ3-O)(µ-piv)6} with an aliphatic diamine ligand. Thermal behavior was investigated for compounds 1 and 2 in an argon atmosphere.

18.
Molecules ; 29(3)2024 Jan 30.
Article in English | MEDLINE | ID: mdl-38338397

ABSTRACT

Zn(II) coordination polymers are being increasingly studied for their stability and properties. Similarly, there is a growing interest in imidazo[1,5-a]pyridine derivatives, which show great potential in luminescence and pharmaceutical applications. In this work, we successfully synthesized and crystallized three new coordination polymers, using Zn(II) as the metallic node, dicarboxylic acids of different length and nature as linkers, and a linear ditopic imidazo[1,5-a]pyridine derivative, to explore the role of this molecule as a propagator of the dimensionality of the structure or as an ancillary ligand. Our work demonstrates the structural capability of imidazo[1,5-a]pyridines in an unexplored domain for this family of ligands. Notably, we observed a pronounced ability of this heterocyclic scaffold to establish π···π interactions in the solid state. The supramolecular π-stacked assemblies were theoretically analyzed using DFT calculations based on model structures.

19.
Angew Chem Int Ed Engl ; 63(18): e202402526, 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38415379

ABSTRACT

Electrically conductive metal-organic frameworks (MOFs) are promising candidates for electrochemical capacitors (EC) for fast energy storage due to their high specific surface areas and potential for redox activity. To maximize energy density, traditional inorganic pseudocapacitors have utilized faradaic processes in addition to double-layer capacitance. Although conductive MOFs are usually comprised of redox active ligands which allow faradaic reactions upon electrochemical polarization, systematic studies providing deeper understanding of the charge storage processes and structure-function relationships have been scarce. Here, we investigate the charge storage mechanisms of a series of triazatruxene-based 2D layered conductive MOFs with variable alkyl functional groups, Ni3(HIR3-TAT)2 (TAT=triazatruxene; R=H, Et, n-Bu, n-Pent). Functionalization of the triazatruxene core allows for systematic variation of structural parameters while maintaining in-plane conjugation between ligands and metals. Specifically, R groups modulate interlayer spacing, which in turn shifts the charge storage mechanism from double-layer capacitance towards pseudocapacitance, leading to an increase in molar specific capacitance from Ni3(HIH3-TAT)2 to Ni3(HIBu3-TAT)2. Partial exfoliation of Ni3(HIBu3-TAT)2 renders redox active ligand moieties more accessible, and thus increases the dominance of faradaic processes. Our strategy of controlling charge storage mechanism through tuning the accessibility of redox-active sites may motivate further design and engineering of electrode materials for EC.

20.
Angew Chem Int Ed Engl ; 63(3): e202316998, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38017354

ABSTRACT

H2 O2 is a widely used eco-friendly oxidant and a potential energy carrier. Photocatalytic H2 O2 production from water and O2 is an ideal approach with the potential to address the current energy crisis and environmental issues. Three zig-zag two-dimensional coordination polymers (2D CPs), named CuX-dptz, were synthesized by a rapid and facile method at room temperature, showing preeminent H2 O2 photoproduction performance under pure water and open air without any additives. CuBr-dptz exhibits a H2 O2 production rate high up to 1874 µmol g-1 h-1 , exceeding most reported photocatalysts under this condition, even comparable to those supported by sacrificial agents and O2 . The coordination environment of Cu can be modulated by halogen atoms (X=Cl, Br, I), which in turn affects the electron transfer process and finally determines the reaction activity. This is the first time that 2D CPs have been used for photocatalytic H2 O2 production in such challenging conditions, which provides a new pathway for the development of portable in situ H2 O2 photosynthesis devices.

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