Search

[Display omitted] Currently, the development of economical and effective non-noble metal electrocatalysts is vital for advancing hydrogen evolution reaction (HER) and enabling its widespread applications. The customizable pore structure and enormous surface area of metal–organic frameworks (MOFs) have made them to become promising non-noble metal electrocatalysts for HER. However, MOFs have some challenges, including low conductivity and instability, which can result in them having high overpotentials and slow reaction kinetics in electrocatalytic processes. In this work, we present an innovative approach for synthesizing cost-effective and high-efficient Zr-MOF-derived pH-universal electrocatalysts for HER. It entails creating the interfaces of the electrocatalysts with suitable proportions of phosphide nanostructures. Zr-MOF/Ni 2 P@nickel foam (NF) electrodes with interface regulated by Ni 2 P nanostructures were successfully developed for high-efficient pH-universal HER electrocatalysts. The presence of Ni 2 P nanostructures with abundant active sites at the Zr-MOFs@NF interfaces boosted the electronic conductivity and local charge density of the hybrid electrocatalysts. This helped to improve their reaction kinetics and electrocatalytic activity. By optimizing the Ni 2 P amount, Zr-MOF/Ni 2 P@NF demonstrated impressive stability and superior HER activities, with a low overpotential of 149 mV (acidic electrolytes) and 143 mV (alkaline electrolytes) at 10 mA cm−2. The proven strategy in this work can be expanded to many types of MOF-based materials for wider practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] As a typical transition-metal sulfides (TMS), nickel disulfide (NiS 2) has attracted great attention in terms of hydrogen evolution reaction (HER). Howbeit, owing to the poor conductivity, slow reaction kinetics and instability of NiS 2 , its HER activity is still necessary to be improved. In this work, we designed hybrid structures consisting of the nickel foam (NF) as a self-supporting electrode, NiS 2 derived from the sulfuration of NF and Zr-MOF grown on the surface of NiS 2 @NF (Zr-MOF/NiS 2 @NF). Due to the synergistic effect between the different constituents, the obtained Zr-MOF/NiS 2 @NF demonstrates ideal electrochemical hydrogen evolution ability in acidic and alkalescent environment, reaching a standard current density of 10 mA cm−2 at overpotentials of 110 and 72 mV in 0.5 M H 2 SO 4 and 1 M KOH electrolytes, respectively. What is more, it also maintains excellent electrocatalytic durability for 10 h in both electrolytes. This work could provide a useful guidance on effectively combining metal sulfide with MOF for high-performance HER electrocatalysts. [ABSTRACT FROM AUTHOR]

In the present work, porous Co 3 O 4 was easily prepared via thermal decomposition of metal-organic frameworks (MOFs). TG, FT-IR, XRD, SEM, TEM and N 2 adsorption-desorption were employed for characterizing the synthesized products. Based on cataluminescence (CTL) transduction principle, three MOFs including dodecahedra ZIF-67, nanosheets packed Co-MOF-71, nanoplate Co-BTC, and their corresponding derivatives Co 3 O 4 were used as sensing materials for H 2 S detection, respectively. The dodecahedra ZIF-67-derived dodecahedra Co 3 O 4 with high specific surface and exposed {110} lattice planes presented superior strong CTL property, and had a good linear relation in the concentration range of 3.3–27.5 μg L −1 with the detection limit of 1 μg L −1 (S/N = 3), while the original MOFs displayed no CTL signal. Eighteen common volatile organic compounds (VOCs) were investigated as possible interference, and the results indicated that MOFs-derived porous dodecahedra Co 3 O 4 would be one of excellent sensing material candidates for monitoring H 2 S with a promising application in routine analysis. [ABSTRACT FROM AUTHOR]

The design of high-performance electrode materials with excellent desalination ability has always been a research goal for efficient capacitive deionization (CDI). Herein, a hybrid architecture with Cu/Cu 2 O nanospheres anchored on porous carbon nanosheets (Cu/Cu 2 O/C) was first synthesized by pyrolyzing a two-dimensional (2D) Cu-based metal-organic framework and then evaluated as a cathode for hybrid CDI. The as-prepared Cu/Cu 2 O/C exhibits a hierarchically porous structure with a high specific surface area of 305 m2 g−1 and large pore volume of 0.55 cm3 g−1, which is favorable to accelerating ion migration and diffusion. The porous carbon nanosheet matrix with enhanced conductivity will facilitate the Faradaic reactions of Cu/Cu 2 O nanospheres during the desalination process. The Cu/Cu 2 O/C hybrid architecture displays a high specific capacitance of 142.5 F g−1 at a scan rate of 2 mV s−1 in 1 M NaCl solution. The hybrid CDI constructed using the Cu/Cu 2 O/C cathode and a commercial activated carbon anode exhibits a high desalination capacity of 16.4 mg g−1 at an operation voltage of 1.2 V in 500 mg L−1 NaCl solution. Additionally, the hybrid CDI exhibits a good cycling stability with 18.3% decay in the desalination capacity after 20 electrosorption–desorption cycles. Thus, the Cu/Cu 2 O/C composite is expected to be a promising cathode material for hybrid CDI. • Cu/Cu 2 O nanospheres anchored on porous carbon nanosheets were synthesized from MOF. • The hybrid architecture is beneficial to the excellent electrochemical behaviors. • The hybrid architecture exhibits superior desalination performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • An in-situ growth technique is used to construct Sn-based MOFs on MXene (MXene@Sn-MOF) • The introduction of MXene reduces the electron transfer impedance at various states of charge. • MXene@Sn-MOF exhibits remarkable capacity, exceptional rate performance and cycling stability. Due to the poor electron transfer characteristics of metal–organic frameworks (MOFs), they always exhibit subpar kinetic performance in Li-ion storage. To address this issue, herein we innovatively devised an in-situ growth technique to enable the construction of Sn-based MOFs on MXene (MXene@Sn-MOF), thereby enhancing its electron transfer capabilities. According to this optimization, the resulting MXene@Sn-MOF composite exhibits excellent Li-ion storage performance, with a remarkable reversible storage capacity of 1009 mAh/g at 0.1 A/g after 100 cycles. It is worth noting that even at a high current density of 2 A/g, the MXene@Sn-MOF composite still maintains a reversible specific capacity of 540 mAh/g after 500 cycles, demonstrating exceptional rate performance and cycling stability. Continuous electrochemical impedance spectroscopy and galvanostatic intermittent titration technique measurements reveal a significant reduction in electron transfer impedance at various states of charge with the introduction of MXene, accompanied by enhanced ion diffusion capabilities, further confirming the beneficial role of MXene in augmenting the Li-ion storage capacity of Sn-based MOFs. We believe that our work provides a promising avenue for the design of anodes with enhanced fast electron transfer ability for Li-ion storage. [ABSTRACT FROM AUTHOR]

Co/Co 2 P@C Mott-Schottky electrocatalysts were successfully synthesized from Co-MOF and show excellent HER activity owing to the Mott-Schottky effect, synergy effect of Co and Co 2 P and porous carbon shell. Cobalt phosphides, as low cost and abundant non-noble materials for hydrogen evolution reaction (HER), are always constrained by their inferior charge transfer and sluggish intrinsic electrocatalytic kinetics. In this work, carbon-incorporated Co/Co 2 P microspheres (Co/Co 2 P@C) as a novel Mott–Schottky catalyst were synthesized successfully via carbonization and gradual phosphorization of Co based metal-organic frameworks. The unique merits, including Mott-Schottky effect at the interface formed between metal Co and semiconductor Co 2 P, the incorporated carbon-layer on the surface and the spherical structure endow Co/Co 2 P@C with favorable electrical conductivity, preferable kinetics and long-term stability when it was evaluated as electrocatalyst for HER in wide-pH range. As a result, the Co/Co 2 P@C with the optimized phosphorization degree delivers a benchmark current density of 10 mA cm−2 at the low overpotential of 192 and 158 mV in acidic and alkaline electrolytes, respectively, with a remarkable stability (CV cycling for 3000 cycles and continuous electrolysis at the overpotential of 200 mV for 48 h). Therefore, the as-designed Co/Co 2 P@C should be one of the most promising catalysts for HER application. [ABSTRACT FROM AUTHOR]

Abstract Pursuing active, stable, low-cost and well-designed electrode materials with superior rate capability and long-life cycling performance for lithium-ion batteries (LIBs) remains a big challenge. In this work, shuttle-like hollow and porous carbon-coated FeP (FeP@C) structures were synthesized from Fe-based metal-organic frameworks (MOFs) MIL-88 as precursors and used as anodes for LIBs. The FeP@C displays a unique structure with ultrafine FeP nanoparticles distributed in the hollow and porous carbon matrix, which offers large specific surface area and fast charge transfer ability, and alleviates volume change during cycling. As a result, the FeP@C delivers a high maximum lithium storage capacity (902.4 mAh g−1 at 0.1 A g−1 for 100 cycles), superior rate capability (reversible capacity of 416 mAh g−1 at 5.0 A g−1) and long-life cycling performance (3000 cycles at 5.0 A g−1). The excellent electrochemical performance is related to significant contribution of pseudocapacitive behavior during charge/discharge process, especially at high current density. The current strategy should be promising to synthesize the carbon-coated porous structure from MOFs for next-generation energy-storage application. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

Smart design and rational fabrication of novel anode materials with high specific capacity and long cycling stability are of significant importance for high-performance lithium-ion batteries (LIBs). Herein, nanostructured ZnO/NiO microspheres with a nanorods-composed shell and a microsphere yolk were synthesized by a controlled calcination treatment of the bimetallic organic frameworks in air. The obtained yolk-shell ZnO/NiO microspheres are observed to have an average diameter of 2 μm with uniform microsphere morphology from field-emission scanning electron microscopy and high-resolution transmission electron microscopy. Benefitting from the unique yolk-shell structure inherited from the bimetallic organic frameworks and the synergistic effect from ZnO and NiO, the as-prepared yolk-shell ZnO/NiO displays excellent lithium storage performance, including high specific capacity (1008.6 mAh g −1 at 0.1 A g −1 after 200 cycles), superior rate capability (437.1 mAh g −1 at 2 A g −1 ) and outstanding long-term cycling stability (592.4 mAh g −1 at 0.5 A g −1 after 1000 cycles), which demonstrates its promising potential as high-performance anode material for LIBs. [ABSTRACT FROM AUTHOR]

In this work, porous NiO microspheres interconnected by carbon nanotubes (NiO/CNTs) were successfully fabricated by the pyrolysis of nickel metal-organic framework precursors with CNTs and evaluated as anode materials for lithium-ion batteries (LIBs). The structures, morphologies, and electrochemical performances of the samples were characterized by X-ray diffraction, N2 adsorption-desorption, field emission scanning electron microscopy, cyclic voltammetry, galvanostatic charge/discharge tests, and electrochemical impedance spectroscopy, respectively. The results show that the introduction of CNTs can improve the lithium-ion storage performance of NiO/CNT composites. Especially, NiO/CNTs-10 exhibits the highest reversible capacity of 812 mAh g−1 at 100 mA g−1 after 100 cycles. Even cycled at 2 A g−1, it still maintains a stable capacity of 502 mAh g−1 after 300 cycles. The excellent electrochemical performance of NiO/CNT composites should be attributed to the formation of 3D conductive network structure with porous NiO microspheres linked by CNTs, which benefits the electron transfer ability and the buffering of the volume expansion during the cycling process. [ABSTRACT FROM AUTHOR]

Recently sodium ion batteries (SIBs) as a new energy storage system have attracted enormous interests. Unfortunately, the development of high-performance electrode materials for SIBs is restricted owing to the large volume change during sodium insertion and extraction. In this work, porous CoFe 2 O 4 nanocubes (PCFO-NCs) were prepared simply by annealing metal-organic frameworks and used as anode materials for SIBs. The PCFO-NCs exhibit a high initial Coulombic efficiency of 68.8% and a maximum reversible capacity of 360 mAh g −1 after 50 cycles at the current density of 50 mA g −1 , as well as good rate capability and excellent cycling stability at high current density. The excellent electrochemical performance can be attributed the short diffusion distance of sodium ion due to the good interfacial contact between electrode and electrolyte, and the buffering of volume change during charge/discharge processes by the porous structure. [ABSTRACT FROM AUTHOR]

Porous MnO@C nanorods were synthesized simply by annealing Mn-based metal-organic frameworks precursor. The morphology, structure and electrochemical performance of MnO@C hybrid were characterized by scanning electron microscopy, nitrogen adsorption/desorption isotherms, galvanostatic charge/discharge tests, cyclic voltammetry and electrochemical impendence spectroscopy. When used as anode material for sodium-ion batteries, the MnO@C hybrid exhibits a high reversible specific capacity of 260 mAh g −1 after 100 cycles at a current density of 50 mA g −1 . When the current density is increased to 2 A g −1 , the MnO@C delivers a superior long-life cycling performance with a capacity of 140 mAh g −1 at very high current density of 2 A g −1 . The excellent electrochemical performance of MnO@C can be attributed to its unique porous structure with MnO nanoparticles embedded in carbon matrix, which can apparently increase the electrical conductivity and buffer the volume change during the charge/discharge process. [ABSTRACT FROM AUTHOR]

Currently, metal-organic frameworks (MOFs) and their derivates have attracted great interest as a new kind of electrode material for energy storage devices, mainly due to their designable framework structures, abundant pore structures, adjustable pore and particle sizes. In this work, porous CuO/reduced graphene oxide (RGO) composites were obtained through the pyrolysis of Cu-based MOFs/graphene oxide under microwave irradiation, and investigated as anode materials for sodium-ion batteries (SIBs). CuO/RGO composites exhibit a maximum specific capacity of 466.6 mA h g −1 after 50 galvanostatic charge/discharge cycles at a current density of 100 mA g −1 . Even at a high current density of 2 A g −1 , a capacity of 347.6 mA h g −1 is still maintained with stable cycling. The superior electrochemical performance, which is better than those of CuO-based electrodes reported previously, makes the CuO/RGO composites to be applied promisingly as anodes for high-performance SIBs. [ABSTRACT FROM AUTHOR]

Porous cake-like TiO 2 was prepared simply by annealing Ti-based metal-organic frameworks templates. The morphology, structure and electrochemical performance of porous TiO 2 were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption-desorption, galvanostatic charge/discharge test, cyclic voltammetry and electrochemical impedance spectroscopy. When used as an anode for sodium ion batteries, porous TiO 2 exhibits a maximum charge capacity of 250 mAh g −1 after 50 cycles at a current density of 50 mA g −1 and delivers a remarkably stable reversible capacity of 173 mA g −1 after 2500 cycles even at a high current density of 1 A g −1 . The excellent electrochemical performance is attributed to the unique porous structure and suitable pore size of porous TiO 2 . [ABSTRACT FROM AUTHOR]

Capacitive deionization (CDI) is an emerging desalination technology that has attracted wide attention. Generally, porous carbons with high specific surface area are considered as ideal electrode materials for CDI application. Despite the progress achieved to date, synthesis of porous carbons with a controllable specific surface area has rarely succeeded. To address this issue, here a new strategy to prepare high-performance CDI electrode materials was proposed by direct carbonization of Zn-containing metal-organic frameworks (MOFs). The results indicate that through controlling Zn/C ratio in MOFs, the resultant porous carbons display a controllable specific surface area, and thus exhibit a superior electrosorption performance. It should be believed that the strategy in this work will provide an effective route to prepare high-performance CDI electrode materials. [ABSTRACT FROM AUTHOR]

Mn-based oxides are efficient pseudocapacitive electrode materials and have been investigated for capacitive deionization (CDI). However, their poor conductivity seriously affects their desalination performance. In this work, polyaniline coated Mn 2 O 3 nanorods (PANI/Mn 2 O 3) are synthesized by oxidizing a Mn-based metal organic framework (MOF) and subsequent in-situ chemical polymerization. The polyaniline not only acts as a conductive network for faradaic reactions of Mn 2 O 3 , but also enhances the desalination rate. PANI/Mn 2 O 3 has a specific capacitance of 87 F g−1 (at 1 A g−1), superior to that of Mn 2 O 3 nanorod (52 F g−1 at 1 A g−1). The hybrid CDI cell constructed with a PANI/Mn 2 O 3 cathode and an active carbon anode shows a high desalination capacity of 21.6 mg g−1, superior recyclability with only 11.3% desalination capacity decay after 30 desalination cycles and fast desalination rate of 2.2 mg g−1 min−1. PANI/Mn 2 O 3 is a potential candidate for high performance CDI applications. • PANI coated Mn 2 O 3 nanorod was synthesized by annealing Mn-MOF and polymerizing. • PANI was used to improve the conductivity and porosity of Mn 2 O 3 materials. • PANI/Mn 2 O 3 exhibited superior desalination performances. [ABSTRACT FROM AUTHOR]

[Display omitted] • MOFs derived NaTi 2 (PO 4) 3 /C with controllable surface morphology was synthesized. • NaTi 2 (PO 4) 3 /C was used as cathode of hybrid capacitive deionization. • The cube/sphere-shaped NaTi 2 (PO 4) 3 /C displayed the best desalination performance. • The relation between surface morphology and desalination performance was studied. Hybrid capacitive deionization (HCDI), as a major branch of capacitive deionization (CDI), was acknowledged as one of the most promising electrochemical desalination techniques due to its ultrahigh desalination capacity and charge efficiency. Among various HCDI electrode materials, polyanion compounds (NaTi 2 (PO 4) 3 (NTP) for instance) have attracted great attention owing to their stable 3D crystal structure and high theoretical capacity. Yet, an important correlation between the surface morphology and desalination performance of the NTP-based composite is still missing, which has become a limitation for the further development of NTP-based HCDI. Herein, we prepared a series of NaTi 2 (PO 4) 3 /Carbon (NTP/C) composites from metal-organic frameworks with different surface morphologies and subsequently used them as the cathode for HCDI. After systematical study, we found that the surface morphology of the NTP/C has a significant impact on its desalination performance, while the cube/sphere-shaped NTP/C exhibits the highest desalination capacity (74.6 mg g−1) with outstanding long-term stability (only 10 % capacity fading after 35 cycles). The vastly different desalination performance indicates that the surface morphology could greatly affect the "packing density" and charge transfer resistance of the NTP/C, and subsequently influence its desalination performance. [ABSTRACT FROM AUTHOR]