Three-dimensional Porous Framework Research Articles

Composite solid electrolyte with Li+ conducting 3D porous garnet-type framework for all-solid-state lithium batteries

A PEO-based composite solid electrolyte (CSE) reinforced by a three-dimensional (3D) porous garnet-type framework is reported.

Dynamic range boosting for electrochemical sensing by morphological optimization of three-dimensional silicon porous framework@Au nanoparticles

Herein we would like to introduce a general method for improving the dynamic range for electrochemical sensing devices based on 3D porous electrodes by morphological optimization. As a showcase, a series of Au nanoparticles integrated three-dimensional silicon-based porous frameworks working electrodes (3D-pSi@AuNP) with the array height ranging between 20 µm and 120 µm are prepared by a combination of metal-assisted chemical etching and surface defects induced isotropic etching in HF/H2O2 mixture and Galvanic displacement, and their electrochemical sensing performance for H2O2 are investigated by voltametric and amperometric methods in detail. The experimental results show that, as the array height of 3D-pSi was increased from 20 µm to 120 µm, the electrochemical active surface area (EASA) was raised by nearly 6 folds, and the upper limit of linear range of detection of H2O2 can be boosted from 4.39 mM to 32.30 mM. With the optimization of Au deposition, it could be further increased to 56.57 mM. We expect this approach to be one of the general methodologies for the improvement of electrochemical sensing devices, especially for those scenarios where the fast detection of high concentration of H2O2 is critical, such as fuel cell and other catalytic oxygen reduction reaction systems.

Composite polymer electrolyte with three-dimensional ion transport channels constructed by NaCl template for solid-state lithium metal batteries

In order to meet the challenges brought by the low ionic conductivity of solid-state electrolytes (SSEs) and the growth of lithium dendrites in all-solid-state lithium metal batteries (ASSLMBs), the composite polymer electrolytes (CPEs) constructed by the combination of three-dimensional (3D) porous ceramics framework and polymers have been widely studied. However, there are still many challenges to preparation of 3D high-strength porous ceramics framework by a simple way. Here, we designed a 3D interconnected porous Li1.3Al0.3Ti1.7(PO4)3 (LATP) framework using NaCl as the template, which not only provides the fast transport channels for Li+ but also serves as a physical barrier to suppress the growth of Li dendrites. Benefiting from the enhanced mechanical and ionic conductivity of the 3D interconnected porous LATP framework, Li/Li symmetric cells based on the prepared CPE can cycle over 1000 h at 0.2 mA cm−2, 0.2 mAh cm−2 and 2000 h at 0.1 mA cm−2, 0.1 mAh cm−2. Moreover, all-solid-state LFP/Li with this 3D CPE demonstrates long-term stability cycles at 1 C.

Effective Enrichment of Low-Concentration Rare-Earth Ions by Three-Dimensional Thiostannate K2Sn2S5.

Rare-earth elements (REEs) in industrial wastewaters have great value for recycling and reuse, but their characteristic of low concentration poses a challenge to an efficient enrichment from wastewaters. In recent years, thiometallates featuring two-dimensional layers have shown great potential in the enrichment of REEs via the ion-exchange process. However, investigations on thiometallates featuring three-dimensional anionic frameworks for the recovery of REEs have not been reported. Herein, K2Sn2S5 (KTS-2), a thiostannate possessing a three-dimensional porous framework, was chosen as an ion-exchange material for capturing REEs from an aqueous solution. Indeed, KTS-2 exhibited excellent ion-exchange performance for all 16 REEs (except Pm). Specifically, KTS-2 displayed a high capture capacity (232.7 ± 7.8 mg/g) and a short equilibrium time (within 10 min) for Yb3+ ions. In addition, KTS-2 had a high distribution coefficient for Yb3+ ions (Kd > 105 mL/g) in the presence of excessive interfering ions. Impressively, KTS-2 could reach removal rates of above 95% for all 16 REEs in a large quantity of wastewater with low initial concentration (∼7 mg/L). Moreover, KTS-2 could be used as an eco-friendly material for ion exchange of REEs, since the released K+ cations would not cause secondary pollution to the water solution.

Synthesis of Si/Fe2O3-Anchored rGO Frameworks as High-Performance Anodes for Li-Ion Batteries.

By virtue of the high theoretical capacity of Si, Si-related materials have been developed as promising anode candidates for high-energy-density batteries. During repeated charge/discharge cycling, however, severe volumetric variation induces the pulverization and peeling of active components, causing rapid capacity decay and even development stagnation in high-capacity batteries. In this study, the Si/Fe2O3-anchored rGO framework was prepared by introducing ball milling into a melt spinning and dealloying process. As the Li-ion battery (LIB) anode, it presents a high reversible capacity of 1744.5 mAh g−1 at 200 mA g−1 after 200 cycles and 889.4 mAh g−1 at 5 A g−1 after 500 cycles. The outstanding electrochemical performance is due to the three-dimensional cross-linked porous framework with a high specific surface area, which is helpful to the transmission of ions and electrons. Moreover, with the cooperation of rGO, the volume expansion of Si is effectively alleviated, thus improving cycling stability. The work provides insights for the design and preparation of Si-based materials for high-performance LIB applications.

A 3D ultramicroporous porous organic frameworks for SO2 and aromatic sulfides capture with high capacity and selectivity

The governance of sulfur dioxide emissions in the atmosphere is a global challenge. Herein, a three-dimensional ultramicroporous porous organic framework named TAM-POF with high surface areas, abundant accessible N sites and suitable pore size was synthesized for elimination of SO2 in flue gases and aromatic sulfides in liquid fuels. The adsorption and separation performance of TAM-POF is investigated by equilibrium gas adsorption, instant adsorption rates and column breakthrough experiments. A record-high SO2 dynamic adsorption capacity of 2.92 mmol g−1 in ternary gas mixture (0.5/10/89.5, v/v/v, SO2/CO2/N2) and SO2/CO2 (124) and 3-methylthiophene/n-octane (42) selectivities were achieved in TAM-POF. The strong interaction between adsorbents and TAM-POF, as well as appropriate pore apertures are the main reason for their excellent desulfurization performance, which are also evidenced by theory simulation.

Novel Lanthanide(III) Porphyrin-Based Metal-Organic Frameworks: Structure, Gas Adsorption, and Magnetic Properties.

The present work focuses on the hydrothermal synthesis and properties of porous coordination polymers of metal–porphyrin framework (MPF) type, namely, {[Pr4(H2TPPS)3]·11H2O}n (UPJS-10), {[Eu/Sm(H2TPPS)]·H3O+·16H2O}n (UPJS-11), and {[Ce4(H2TPPS)3]·11H2O}n (UPJS-12) (H2TPPS = 4,4′,4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrakisbenzenesulfonate(4-)). The compounds were characterized using several analytical techniques: infrared spectroscopy, thermogravimetric measurements, elemental analysis, gas adsorption measurements, and single-crystal structure analysis (SXRD). The results of SXRD revealed a three-dimensional open porous framework containing crossing cavities propagating along all crystallographic axes. Coordination of H2TPPS4– ligands with Ln(III) ions leads to the formation of 1D polymeric chains propagating along the c crystallographic axis. Argon sorption measurements at −186 °C show that the activated MPFs have apparent BET surface areas of 260 m2 g–1 (UPJS-10) and 230 m2 g–1 (UPJS-12). Carbon dioxide adsorption isotherms at 0 °C show adsorption capacities up to 1 bar of 9.8 wt % for UPJS-10 and 8.6 wt % for UPJS-12. At a temperature of 20 °C, the respective CO2 adsorption capacities decreased to 6.95 and 5.99 wt %, respectively. The magnetic properties of UPJS-10 are characterized by the presence of a close-lying nonmagnetic ground singlet and excited doublet states in the electronic spectrum of Pr(III) ions. A much larger energy difference was suggested between the two lowest Kramers doublets of Ce(III) ions in UPJS-12. Finally, the analysis of X-band EPR spectra revealed the presence of radical spins, which were tentatively assigned to be originating from the porphyrin ligands.

Single Co atoms anchored on nitrogen-doped hierarchically ordered porous carbon for selective hydrogenation of quinolines and efficient oxygen reduction

Constructing ordered macro-mesoporous carbon with nonprecious metal single-atom sites to improve the utilization rate of the inaccessible active sites inside the carbon can significantly facilitate its catalytic performance and reduce costs. Herein, by elaborate design, we pyrolyze ordered macro-microporous bimetallic single-crystalline ZnCo-ZIFs to fabricate single Co atoms anchored on N-doped hierarchically ordered porous carbon (Co-SAs@NHOPC) that showed an excellent yield of 99% and outstanding selectivity of > 99% for quinolines hydrogenation reaction (QHR). Besides, the obtained Co-SAs@NHOPC also exhibited excellent performance for the oxygen reduction reaction (ORR) in 0.1 M KOH with a half-wave potential of 0.851 V versus reversible hydrogen electrode (RHE). The as-obtained Co-SAs@NHOPC structure is the exquisite integration of the three-dimensional (3D) bicontinuous porous frameworks, the inherited micropores within N-doped carbon skeletons, well-defined tetrakaidecahedron morphology, and atomically dispersed Co atoms. The 3D hierarchical porous characteristics allow the reactants to contact the active sites inside the N-doped carbon and improve the mass transfer efficiency, thereby improving the atom utilization rate for QHR and ORR.

Metal-Organic Framework Derived Ultrafine Sb@Porous Carbon Octahedron via In Situ Substitution for High-Performance Sodium-Ion Batteries.

Alloying-type anode materials are regarded as promising alternatives beyond intercalation-type carbonaceous materials for sodium storage owing to the high specific capacities. The rapid capacity decay arising from the huge volume change during Na+-ion insertion/extraction, however, impedes the practical application. Herein, we report an ultrafine antimony embedded in a porous carbon nanocomposite (Sb@PC) synthesized via facile in situ substitution of the Cu nanoparticles in a metal-organic framework (MOF)-derived octahedron carbon framework for sodium storage. The Sb@PC composite displays an appropriate redox potential (0.5-0.8 V vs Na/Na+) and excellent specific capacities of 634.6, 474.5, and 451.9 mAh g-1 at 0.1, 0.2, and 0.5 A g-1 after 200, 500, and 250 cycles, respectively. Such superior sodium storage performance is primarily ascribed to the MOF-derived three-dimensional porous carbon framework and ultrafine Sb nanoparticles, which not only provides a penetrating network for rapid transfer of charge carriers but also alleviates the agglomeration and volume expansion of Sb during cycling. Ex situ X-ray diffraction and in situ Raman analysis clearly reveal a five-stage reaction mechanism during sodiation and desodiation and demonstrate the excellent reversibility of Sb@PC for sodium storage. Furthermore, post-mortem analysis reveals that the robust structural integrity of Sb@PC can withstand continuous Na+-ion insertion/extraction. This work may provide insight into the effective design of high-capacity alloying-type anode materials for advanced secondary batteries.

Co/N co-doped carbonized wood sponge with 3D porous framework for efficient peroxymonosulfate activation: Performance and internal mechanism

Renewable wood sponge with lamellar structure, compressibility and three-dimensional porous frameworks exhibits excellent functionalization application potential in various fields. Herein, cobalt and nitrogen (Co/N) co-doped carbonized wood sponge (CoNCWS800) was prepared successfully for peroxymonosulfate (PMS) activation to degrade sulfamethoxazole (SMX). The CoNCWS800 material exhibited admirable catalytic activity in PMS activation to oxidize SMX molecules (99.7% within 60 min). Electron paramagnetic resonance (EPR) analysis, quenching tests and electrochemical experiments confirmed the existence of both radical (SO4·−,·OH and O2·−) and non-radical (1O2 and direct charge transfer) pathways during the SMX degradation process. Co species were verified as major contributors for the generation of multiple radicals via activating PMS. Surface defective structure and ketonic CO groups performed the positive linear correlation with reaction kinetic constants, revealing the critical role of the two active sites in PMS activation via non-radical process. This study provides a unique insight in PMS activation mechanism via both radical and non-radical pathways of wood sponge-based functional materials.

Three-dimensional porous N-doped graphitic carbon framework with embedded CoO for photocatalytic CO2 reduction

A facile polymer thermal treatment method has been employed to fabricate 3D porous N-doped graphitic carbon frameworks with embedded CoO (CoO@N-GCs), which are employed as catalysts for the photocatalytic reduction of CO2. The experimental results demonstrate that the CoO@N-GC-500 catalyst exhibits excellent photocatalytic performance and stability for the photoreduction of CO2 in water. Under visible light irradiation, the maximum yields for CH4 and CO are 10.03 μmol/(h·g) and CO is 5.16 μmol/(h·g), respectively. The high photocatalytic performance of CoO@N-GC-500 is attributed to the efficient separation of the photogenerated electron-hole pairs, large specific surface area, and strong visible light absorption capacity. This work paves a new way for the practical application of the CoO catalysts in artificial photosynthesis.

Nano-channel-based physical and chemical synergic regulation for dendrite-free lithium plating

Uncontrollable dendrite growth resulting from the non-uniform lithium ion (Li+) flux and volume expansion in lithium metal (Li) negative electrode leads to rapid performance degradation and serious safety problems of lithium metal batteries. Although N-containing functional groups in carbon materials are reported to be effective to homogenize the Li+ flux, the effective interaction distance between lithium ions and N-containing groups should be relatively small (down to nanometer scale) according to the Debye length law. Thus, it is necessary to carefully design the microstructure of N-containing carbon materials to make the most of their roles in regulating the Li+ flux. In this work, porous carbon nitride microspheres (PCNMs) with abundant nanopores have been synthesized and utilized to fabricate a uniform lithiophilic coating layer having hybrid pores of both the nano- and micrometer scales on the Cu/Li foil. Physically, the three-dimensional (3D) porous framework is favorable for absorbing volume changes and guiding Li growth. Chemically, this coating layer can render a suitable interaction distance to effectively homogenize the Li+ flux and contribute to establishing a robust and stable solid electrolyte interphase (SEI) layer with Li-F, Li-N, and Li-O-rich contents based on the Debye length law. Such a physical-chemical synergic regulation strategy using PCNMs can lead to dendrite-free Li plating, resulting in a low nucleation overpotential and stable Li plating/stripping cycling performance in both the Li‖Cu and the Li‖Li symmetric cells. Meanwhile, a full cell using the PCNM coated Li foil negative electrode and a LiFePO4 positive electrode has delivered a high capacity retention of ∼ 80% after more than 200 cycles at 1 C and achieved a remarkable rate capability. The pouch cell fabricated by pairing the PCNM coated Li foil negative electrode with a NCM 811 positive electrode has retained ∼ 73% of the initial capacity after 150 cycles at 0.2 C.

One-pot synthesis of Mn2P-Mn2O3 heterogeneous nanoparticles in a P, N -doped three-dimensional porous carbon framework as a highly efficient bifunctional electrocatalyst for overall water splitting

Robust, inexpensive, efficient catalysts for overall water splitting are of significant interest as we look towards the Hydrogen Economy. Herein, we have prepared novel Mn2P-Mn2O3 heterogeneous nanoparticles hosted in a P, N-doped three-dimensional porous carbon framework. Of these, Mn2P-Mn2O3/PNCF displayed ultrahigh stability as a bifunctional electrocatalyst for efficient hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs) in alkaline electrolytes. These properties are a result of the abundant heterogeneous interfaces, optimized electronic configurations and hierarchical pore structure of the Mn2P-Mn2O3/PNCF catalyst. This material has a closed zero calculated Gibbs free energy for adsorbed H of −0.013 eV, and can achieve current densities of 10 mA cm−2 and 100 mA cm−2 for HERs and OERs, respectively, whilst requiring only low overpotentials of 98 mV and 330 mV, respectively. In addition, an alkaline electrolyzer with Mn2P-Mn2O3/PNCF as both the anode and cathode demonstrates a nearly comparable activity and higher stability than the present state‐of‐the‐art, Pt/C || RuO2/C, for full water splitting. Mn2P-Mn2O3/PNCF shows great potential for the economical, large-scale production of H2.

Four coordination polymers based on 5-(3,5-dicarboxybenzyloxy) isophthalic acid: Synthesis, structures, photocatalytic properties, fluorescence sensing and magnetic properties

Four coordination polymers named [Co(L)0.5(bib)]n(1), Zn(H2L)(bib)]·2H2O}n(2), Cd(L)0.5(1,2-bimb)]n(3) and Zn(L)0.5(bib)]n(4) (H4L ​= ​5-(3,5-dicarboxybenzyloxy) isophthalic acid, bib ​= ​1,4-bis(1-imidazolyl)benzene, and 1,2-bimb ​= ​1,2-bis(1-imidazolylmethyl)benzene) were synthesized by solvothermal method and structurally characterized by means of single-crystal X-ray diffraction, infrared spectra and elemental analyses. Complex 1 crystallized in orthorhombic space group Pbcn had a 2-fold interpenetrated framework. Complex 2 showed a 4-fold interpenetrated framework. Complex 3 presented a 3-fold interpenetrated framework that crystallized in the triclinic system Pī space group. Complex 4 was a three-dimensional (3D) porous framework. Remarkably, the photocatalytic degradation experiments of complexes 1–4 on methylene blue (MB) indicated that these complexes 1–4 exhibited obvious degradation effect on MB. Moreover, the investigation of the luminescent properties of complexes 2–4 revealed that these complexes 2–4 could be served as a potential highly selective Fe3+ ion luminescent sensor. In addition, the magnetic analyses of complex 1 indicated that there was antiferromagnetic interaction between the Co (II) ions in complex 1.

Anionic three-dimensional porous aromatic framework for fast Li-ion conduction

Solid polymer electrolytes (SPEs) have been received significant attention due to their inherent advantages of high safety and high electrochemical stability as fast Li-ion conductors. However, conventional SPEs of dual-ion conductors (i.e., conducting both anions and cations) are prone to induce concentration polarization and thus decrease in ionic conductivities, which remains a significant hurdle for their practical applications. Here, we propose a new host of porous aromatic frameworks (PAFs) as a promising single Li-ion conducting SPEs. PAF1 is one of the promising types for crystalline polymers with the integration of aromatic organic building units into a 3-dimensional framework, having plenty of voids space inside. By covalently tethering the sulfonate on aromatic groups, anions are immobilized onto the frameworks, and the exchanging process of protons with Li-ions makes it perform as a fast Li-ionic conductor. Consequently, Li sulfonated PAF1 (denoted as Li-SPAF1) shows superior ion-conducting properties of 0.102 mS cm−1 at room temperature with the activation energy of 0.21 eV. It is demonstrated that the aromatic groups have high chemical and thermal stabilities, even stable with Li metal, which is advantageous for delivering stable electrochemical performances. Also, the structure and conduction mechanism are theoretically investigated by using density functional theory calculations.

Robust Silica–Polyimide Aerogel Blanket for Water-Proof and Flame-Retardant Self-Floating Artificial Island

A robust silica–polyimide (PI) aerogel blanket is designed and synthesized using the PI foam as the matrix and silica aerogel as the filler through an in situ method, where sol–gel transition of silica precursor occurs in pores of the PI foam, followed by the hydrophobization and ambient pressure drying. The density of the aerogel blanket ranges from 0.036 to 0.196 g/cm3, and the low density is directly controlled by tailoring the silica concentration. The specific surface area of the aerogel blanket reaches 728 m2/g. These features of the blanket result in a low thermal conductivity of 0.018 W/mK, which shows a remarkable reduction of 59% compared to that of the PI foam (0.044 W/mK). As a result, a remarkable decrease of 138°C is achieved using the silica blanket as the thermal insulator on a hot plate of approximately 250°C. In addition, the temperature degradation of the blanket is around 500°C, and up to 86% of mass remaining at 900°C is obtained. The blanket is resistant at extremely harsh conditions, e.g., 600°C for 30 min and 1,300°C for 1 min, and no open flame is observed, suggesting a significant flame-retardant of the blanket. Owing to the three-dimensional (3D) porous framework of the PI foam, the silica aerogel is encapsulated in the PI foam and the blanket exhibits strong mechanical property. The silica–PI aerogel can be reversibly compressed for 50 cycles without reduction of strain. The contact angle of the blanket is 153°, which shows a superior waterproof property. Combining with the low density, low thermal conductivity, flame-retardant, and strong mechanical strength, the aerogel blanket has the potential as an artificial island, which is safe (waterproof and flame-retardant), lightweight, comfortable, and easy to be moved.

Bio-inspired construction of ion conductive pathway in covalent organic framework membranes for efficient lithium extraction

Summary As the most sophisticated separation system, biological membranes have served as natural prototypes for the design of artificial membranes because they provide high permeability and solute selectivity, owing to the presence of specialized ion channels. However, developing stable and selective artificial ion channels remains a formidable challenge. Herein, we demonstrate the construction of lithium nanochannels in two-dimensional covalent organic frameworks (COFs) to create biomimetic membranes. Implanted lithiophilic oligoethers conferred specificity and facilitated Li+ diffusion along the pore pathway of the COF. The ion channel characteristics were indicated by reversal potential measurements, showing that the relative permeability decreased in the order Li+ > K+ > Na+ > Ca2+ > Mg2+. The Li+ transfer was enhanced, while other ions were obstructed, allowing for high selectivity and permeability. A Li+/Mg2+ separation factor of 64 was achieved, confirming high lithium affinity. This study may serve as a design principle to develop selective artificial membranes for effective ion separation.

Polydopamine functionalized cellulose-MXene composite aerogel with superior adsorption of methylene blue

Incorporation of nanoparticles into a three-dimensional porous framework to enhance adsorption capacity and recyclability of nanomaterial is of great significance for water contamination removal. Herein, a functionalized cellulose/MXene composite aerogel is prepared by the oxidative self-polymerization of dopamine hydrochloride and freeze-drying, which exhibits an excellent adsorption performance for methylene blue (MB). Characterization results show the successful combination of PDA and Ti3C2Tx into the cellulose aerogel with merits of light weight, high structural stability and high porosity. The adsorption process is understood more deeply through the adsorption kinetics. The Langmuir isotherm model was used to better fit the adsorption process, and the maximum adsorption capacity for MB reaches 168.93 mg g−1. Such a superior adsorption ability for MB is maintained in salt-containing water, or even a little higher when the concentration of NaCl is above 3%, recommending the functionalized cellulose/MXene composite aerogel for efficient removal of dyes in high-salt water environment.

Three-dimensional hierarchical porous hard carbon for excellent sodium/potassium storage and mechanism investigation

Hard carbons are one of the most promising anode materials for sodium/potassium-ion batteries (SIBs/PIBs), which demonstrate favorable long charge/discharge plateaus, but suffer from low rate performance. Herein, we report a new design of N–P codoped hard carbon (NPHC) with three-dimensional (3D) hierarchical porous frameworks. Such unique structure provides bicontinuous ion/electron transportation paths, regulated electronic structure, enlarged interlayer spacing, and moderate surface area. The as prepared NPHC demonstrates a high reversible specific capacity (336 mAh g−1 for SIBs, 339 mAh g−1 for PIBs), along with a good rate performance of ~5.3 C. Particularly, an in-depth study on the charge storage mechanism for both SIBs and PIBs is conducted by combining in-situ Raman spectra and quasi in-situ synchrotron X-ray diffraction analysis, whereby the coexistence of physical adsorption/graphitic layer intercalation, or intercalation/pore filling within certain potential ranges is detected, and the ion storage behavior at different charge/discharge stages is precisely identified.

An unprecedented octamolybdate aggregate chain stabilized in a three-dimensional porous framework

A new polyoxometalate (POM)-based compound, {[CuI(bipy)]2[MoV2MoVI6O24]}·H2O (bipy = 4,4’ -bipyridine) was hydrothermally synthesized, and characterized by elemental analyses, FT-IR spectrum, Powder X-Ray diffraction, X-ray photoelectron spectroscopy and single X-ray diffraction. A structural feature of compound 1 is its unprecedented octamolybdate (Mo8) aggregate chain, which was formed via edge-sharing four distorted [MoO6] octahedra of neighbouring Mo8 clusters. An other fascinating structural features of compound 1 is its high-opened framework with rhombic channels constructed by linkages of Mo8 aggregate chains and Cu-bipy coordinated chains. Furthermore, compound 1 exhibits reversible water sorption capability.