| 1. |
- Bao, Zijia, et al.
(författare)
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A bimetallic 3D interconnected metal–organic framework with 2D morphology and its derived electrocatalyst for oxygen reduction
- 2023
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Ingår i: CrystEngComm. - : Royal Society of Chemistry (RSC). - 1466-8033. ; 25:13, s. 1869-1873
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Tidskriftsartikel (refereegranskat)abstract
- Metal–organic frameworks (MOFs) are widely used as precursors to generate derivatives for electrocatalysis. However, two-dimensional (2D) MOFs often suffer from the collapse of their 2D structures after being treated at high temperature. Herein, we used the dense ZIF-EC1 as a precursor and doped Co as a secondary metal. The content of Co in ZIF-EC1 can be tuned without changing the crystalline structure. After pyrolysis, the derived carbon-based material maintains the 2D morphology from the parental precursor. The derived ZIF-EC1(ZnCo)-20-900 exhibits the best activity toward the ORR, which is even better than that of Pt/C. This work demonstrates the potential of using a nonporous dense MOF as a precursor and optimizing electrocatalytic ORR activity by tuning the Co content.
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| 2. |
- Bao, Zijia, et al.
(författare)
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A helical polypyrrole nanotube interwoven zeolitic imidazolate framework and its derivative as an oxygen electrocatalyst
- 2022
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; 58:80, s. 11288-11291
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Tidskriftsartikel (refereegranskat)abstract
- A helical polypyrrole nanotube interwoven zeolitic imidazolate framework (ZIF) has been prepared for the first time. After pyrolysis, the helical carbon could act as highly active sites, while the 3D-connected nanoarchitecture contributed to fast charge transfer. The derived carbon material exhibits high activity for the ORR and good performance for a Zn–air battery.
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| 3. |
- Wang, Yanzhi, et al.
(författare)
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Anchoring Fe Species on the Highly Curved Surface of S and N Co-Doped Carbonaceous Nanosprings for Oxygen Electrocatalysis and a Flexible Zinc-Air Battery
- 2024
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Ingår i: Angewandte Chemie International Edition. - 1433-7851 .- 1521-3773. ; 63:7
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen reduction reaction (ORR) is of critical significance in the advancement of fuel cells and zinc-air batteries. The iron-nitrogen (Fe−Nx) sites exhibited exceptional reactivity towards ORR. However, the task of designing and controlling the local structure of Fe species for high ORR activity and stability remains a challenge. Herein, we have achieved successful immobilization of Fe species onto the highly curved surface of S, N co-doped carbonaceous nanosprings (denoted as FeNS/Fe3C@CNS). The induction of this twisted configuration within FeNS/Fe3C@CNS arose from the assembly of chiral templates. For electrocatalytic ORR tests, FeNS/Fe3C@CNS exhibits a half-wave potential (E1/2) of 0.91 V in alkaline medium and a E1/2 of 0.78 V in acidic medium. The Fe single atoms and Fe3C nanoparticles are coexistent and play as active centers within FeNS/Fe3C@CNS. The highly curved surface, coupled with S substitution in the coordination layer, served to reduce the energy barrier for ORR, thereby enhancing the intrinsic catalytic activity of the Fe single-atom sites. We also assembled a wearable flexible Zn-air battery using FeNS/Fe3C@CNS as electrocatalysts. This work provides new insights into the construction of highly curved surfaces within carbon materials, offering high electrocatalytic efficacy and remarkable performance for flexible energy conversion devices.
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| 4. |
- Wang, Yanzhi, et al.
(författare)
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Fe Single-atom Sites in Two-Dimensional Nitrogen-doped Porous Carbon for Electrocatalytic Oxygen Reduction
- 2022
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Ingår i: ChemCatChem. - : Wiley. - 1867-3880 .- 1867-3899. ; 14:14
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Tidskriftsartikel (refereegranskat)abstract
- The development of electrocatalysts for oxygen reduction reaction (ORR) is important for energy conversion devices, such as fuel cells, and metal-air batteries. Here, we have developed a confined space strategy to prepare a two-dimensional (2D) leaf-like nitrogen (N)-containing porous carbon as a single-atom catalyst substrate. ZIF−L materials have been confined in a thin silica layer to regulate the pyrolysis. The obtained Fe single atoms doped N-containing porous carbons (Fe SAs/N−C) maintain the 2D morphology and have Fe single-atom active sites. Correspondingly, Fe SAs/N−C exhibits excellent ORR performance (E1/2 of 0.907 V), which is more positive than those of commercially available Pt/C (0.874 V) and most reported non-noble metal catalysts. The durability test shows that Fe SAs/N−C exhibits good stability during electrocatalytic process. This rational design shows a new strategy to prepare 2D catalyst supports with single-atom active sites.
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