Nitrogen-doped graphitic porous carbons (NGPCs) have been synthesized by using a zeolite-type nanoscale metal-organic framework (NMOF) as a self-sacrificing template, which simultaneously acts as ...both the carbon and nitrogen sources in a facile carbonization process. The NGPCs not only retain the nanopolyhedral morphology of the parent NMOF, but also possess rich nitrogen, high surface area and hierarchical porosity with well-conducting networks. The promising potential of NGPCs as metal-free electrocatalysts for oxygen reduction reactions (ORR) in fuel cells is demonstrated. Compared with commercial Pt/C, the optimized NGPC-1000-10 (carbonized at 1000 °C for 10 h) catalyst exhibits comparable electrocatalytic activity via an efficient four-electron-dominant ORR process coupled with superior methanol tolerance as well as cycling stability in alkaline media. Furthermore, the controlled experiments reveal that the optimum activity of NGPC-1000-10 can be attributed to the synergetic contributions of the abundant active sites with high graphitic-N portion, high surface area and porosity, and the high degree of graphitization. Our findings suggest that solely MOF-derived heteroatom-doped carbon materials can be a promising alternative for Pt-based catalysts in fuel cells.
Environmentally friendly and efficient transition metal phosphide (TMP) electrocatalysts for oxygen evolution reaction (OER) are developed to meet the growing demand for clean energy. Here we report ...a novel and environmentally friendly strategy for the preparation of MOF-derived bimetallic phosphide embedded in the carbonaceous matrix (FeNiP/C). With 3-dimensional hollow barrel shape and high specific surface, FeNiP/C-900 performs excellent OER catalytic performance, reaching a current density of 10 mA cm−2 at an overpotential of 229 mV with a low Tafel slope of 74.5 mV dec−1. Meantime, we explore the thermal conversion mechanism of P-containing MOF and the compositional changes during heat treatment.
Schematic illustration represents the synthesis of FeNiP/C composite, which is prepared by the self-assembly of Ni2+, H3TPO, and dabco to form BMM-10 microcrystals, followed by the treatment of the Fe3+ etching and direct pyrolyzation. In-situ formed FeNiP nanoparticles anchored on the carbon layer with 3D hollow structure performs an enhanced electrocatalyst activity for OER. Finally, the transformation mechanism of this P-contained BMM-10 is also well explored. Display omitted
•A less toxic strategy to prepare porous MOF-derived transition metal phosphide nano-composites.•The as-obtained hollow FeNiP/C-900 nano-composite possesses the high electrocatalytic activity for OER.•The chemical bond and phase changes are discussed to form FeNiP/C nano-particles.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
Considering the rapid increase of CO
emission, especially from power plants, there is a constant need for materials which can effectively eliminate post-combustion CO
(the main component: CO
/N
= ...15/85). Here, we show the design and synthesis of a Cu(II) metal-organic framework (FJI-H14) with a high density of active sites, which displays unusual acid and base stability and high volumetric uptake (171 cm
cm
) of CO
under ambient conditions (298 K, 1 atm), making it a potential adsorbing agent for post-combustion CO
. Moreover, CO
from simulated post-combustion flue gas can be smoothly converted into corresponding cyclic carbonates by the FJI-H14 catalyst. Such high CO
adsorption capacity and moderate catalytic activity may result from the synergistic effect of multiple active sites.
Water electrolysis is an emerging energy conversion technology, which is significant for efficient hydrogen (H2) production. Based on the high‐activity transition metal ions and metal alloys of ...ultrastable bifunctional catalyst, the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are the key to achieving the energy conversion method by overall water splitting (OWS). This study reports that the Co‐based coordination polymer (ZIF‐67) anchoring on an indium–organic framework (InOF‐1) composite (InOF‐1@ZIF‐67) is treated followed by carbonization and phosphorization to successfully obtain CoP nanoparticles–embedded carbon nanotubes and nitrogen‐doped carbon materials (CoP‐InNC@CNT). As HER and OER electrocatalysts, it is demonstrated that CoP‐InNC@CNT simultaneously exhibit high HER performance (overpotential of 153 mV in 0.5 m H2SO4 and 159 mV in 1.0 m KOH) and OER performance (overpotential of 270 mV in 1.0 m KOH) activities to reach the current density of 10 mA cm−2. In addition, these CoP‐InNC@CNT rods, as a cathode and an anode, can display an excellent OWS performance with η10 = 1.58 V and better stability, which shows the satisfying electrocatalyst for the OWS compared to control materials. This method ensures the tight and uniform growth of the fast nucleating and stable materials on substrate and can be further applied for practical electrochemical reactions.
A type of CoP embedded in carbon nanotubes and nitrogen‐doped carbon material calcined from a bimetallic metal–organic frameworks (MOF) precursor is designed and prepared by growing Co‐based MOFs on an indium–organic framework. The CoP incorporation can greatly promote the water splitting kinetics by the optimized catalyst of CoP‐InNC@CNT, thus the high electrocatalytic activity is achieved toward both the hydrogen evolution reaction and oxygen evolution reaction.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A series of isomorphic lanthanide coordination polymers with 2,6-dimethylpyridine-3,5-dicarboxylic acid (H
2
mpda), formulated as Ln(Hmpda)
3
(H
2
mpda) Ln = Tb (
1
), Eu (
2
), Gd (
3
) and Ln = ...mixed lanthanide (
4
), have been synthesized and structurally characterized. Single-crystal X-ray diffraction reveals that they are isomorphic and each displays a 1D chain-based structure, which can be expanded by hydrogen bond interactions into a 3D supramolecular architecture. In addition, they are thermally stable up to 350 °C and unusually chemically stable in a wide pH range of 2-13, which was confirmed by variable temperature XRD and pH dependent XRD. Meanwhile, the luminescence properties of compounds
1-4
are investigated. Of these, compound
1
acts as a luminescent probe for the sensing of temperature and pH, and compound
4
shows white light emission. Moreover, compounds
1
,
2
and
4
were encapsulated in LED devices, with compound
4
exhibiting warm white light emission with excellent color rendering index (CRI) and correlated color temperature (CCT).
A series of isomorphic of highly chemically and thermally stable lanthanide coordination polymers exhibit luminescent probe and warm white-light emission.
Hollow carbon materials are regarded as crucial support materials in catalysis and electrochemical energy storage on account of their unique porous structure and electrical properties. Herein, an ...indium‐based organic framework of InOF‐1 can be thermally carbonized under inert argon to form indium particles through the redox reaction between nanosized indium oxide and carbon matrix. In particular, a type of porous hollow carbon nanostraw (HCNS) is in situ obtained by combining the fusion and removal of indium within the decarboxylation process. The as‐synthesized HCNS, which possesses more charge active sites, short and quick electron, and ion transport pathways, has become an excellent carrier for electrochemically active species such as iodine with its unique internal cavity and interconnected porous structure on the tube wall. Furthermore, the assembled zinc‐iodine batteries (ZIBs) provide a high capacity of 234.1 mAh g−1 at 1 A g−1, which ensures that the adsorption and dissolution of iodine species in the electrolyte reach a rapid equilibrium. The rate and cycle performance of the HCNS‐based ZIBs are greatly improved, thereby exhibiting an excellent capacity retention rate. It shows a better electrochemical exchange capacity than typical unidirectional carbon nanotubes, making HCNS an ideal cathode material for a new generation of high‐performance batteries.
A type of porous hollow carbon nanostraw (HCNS) is in situ obtained by combining the fusion and removal of metallic indium within the decarboxylation process from InOF‐1 nanorod. The HCNS becomes an excellent carrier for electrochemically active species such as iodine with its unique internal cavity and interconnected porous structure on the tube wall to improve the assembled zinc‐iodine batteries.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The rational design and facile construction of non-noble metal-based electrocatalysts for efficient oxygen reduction reaction (ORR) remain a challenge for the development of clean energy conversion ...devices. Herein, we synthesized a new type of hierarchical hollow carbon nanomaterials through one-step pyrolysis on bimetallic ZIF-Zn/Co precursors. The obtained hollow N-doped carbon composites, denoted as HNCT-CNTs, are enriched with Co-N
x
sites and
in-situ
formed multi-walled carbon nanotubes (CNTs). Theoretical and experimental studies confirmed that the obtained HNCT-CNT exhibits excellent ORR catalytic activity with a reduced energy barrier for ORR intermediates. Owing to these advantages, the optimal catalyst shows an excellent half-wave potential of 0.85 V, a limiting current density up to 6.36 mA cm
−2
, a Tafel slope of 58.2 mV dec
−1
, and robust stability. Furthermore, the assembled Zn-air battery based on HNCT-CNT also displays an open circuit voltage of 1.49 V and a satisfactory power density of 116.56 mW cm
−2
. This template-directed preparation method opens up an interesting and efficient route to fabricate highly active non-noble metal-doped carbon nanomaterials for a wide range of electrochemical energy applications.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The photocatalytic transformation of carbon dioxide (CO2) into carbon‐based fuels or chemicals using sustainable solar energy is considered an ideal strategy for simultaneously alleviating the energy ...shortage and environmental crises. However, owing to the low energy utilization of sunlight and inferior catalytic activity, the conversion efficiency of CO2 photoreduction is far from satisfactory. In this study, a MOF‐derived hollow bimetallic oxide nanomaterial is prepared for the efficient photoreduction of CO2. First, a unique ZIF‐67‐on‐InOF‐1 heterostructure is successfully obtained by growing a secondary Co‐based ZIF‐67 onto the initial InOF‐1 nanorods. The corresponding hollow counterpart has a larger specific surface area after acid etching, and the oxidized bimetallic H‐Co3O4/In2O3 material exhibits abundant heterogeneous interfaces that expose more active sites. The energy band structure of H‐Co3O4/In2O3 corresponds well with the photosensitizer of Ru(bpy)3Cl2, which results in a high CO yield of 4828 ± 570 µmol h−1 g−1 and stable activity over a consecutive of six runs, demonstrating adequate photocatalytic performance. This study demonstrates that the rational design of MOF‐on‐MOF heterostructures can completely exploit the synergistic effects between different components, which may be extended to other MOF‐derived nanomaterials as promising catalysts for practical energy conversion and storage.
In this article, the hollow counterpart of H‐ZIF‐67‐on‐InOF‐1 presents a larger specific surface area after being acid‐etched, and its corresponding bimetallic oxide of H‐Co3O4/In2O3 owns abundant heterogeneous interfaces, which show a satisfactory photocatalytic CO2 reduction.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
With the help of the ligand-oriented method, we have successfully embedded independent copper-based units into the indium-organic framework system for the first time, in which the Cu4I4 clusters and ...In3O(CO2)6 clusters coexist. This heterometallic cluster-based framework has a large porosity with extra-open channels along the c-axis, and its sorption capacity has also been investigated.
PDF
