| 1. |
- Hong, Jie, et al.
(författare)
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Asymmetrically coupled co single-atom and co nanoparticle in double-shelled carbon-based nanoreactor for enhanced reversible oxygen catalysis
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 455
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Tidskriftsartikel (refereegranskat)abstract
- Simultaneous construction of size-asymmetric metal single atoms and nanoparticle active sites in advanced and robust carrier materials is particularly important yet challenging for efficient reversible oxygen catalysis. Herein, a facile “chemical etching/in-Situ capture” synthesis strategy was developed to fabricate a unique double-shelled carbon-based nanobox integrated with size-asymmetric Co single-atom (CoSA) and metallic Co nanoparticle (CoNP) moiety. As expected, this well-managed catalyst product yielded remarkable bifunctional electrocatalytic performances in alkaline electrolytes, with a decent half-wave potential of 0.886 V for oxygen reduction reaction (ORR) and a small overpotential of 341 mV at 10 mA/cm2 for oxygen evolution reaction (OER). Besides, this nanobox catalyst served as a cost-effective and efficient oxygen electrode in the assembled rechargeable ZABs, exceeding the mixed electrocatalyst of expensive Pt/C-RuO2, in terms of the elevated peak power density of 239 mW/cm2, the promoted specific capacity of 770 mAh/gZn, as well as the appreciable charge–discharge cycle stability. Theoretical calculations revealed that the strong interaction between the delicate CoSA site and CoNP phase, could effectively optimize the adsorption and desorption energy barriers of reaction intermediates on the designed catalyst surface, thus achieving synergistic enhancement of electrocatalytic activity towards ORR and OER. This finding affords a feasible and effective strategy to achieve highly active and durable bifunctional catalysts for both fundamental research and practical rechargeable ZABs applications.
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| 2. |
- Jiang, Yan, et al.
(författare)
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Negligible-Pb-Waste and Upscalable Perovskite Deposition Technology for High-Operational-Stability Perovskite Solar Modules
- 2019
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Ingår i: Advanced Energy Materials. - : Wiley-VCH Verlagsgesellschaft. - 1614-6832 .- 1614-6840. ; 9:13
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Tidskriftsartikel (refereegranskat)abstract
- An upscalable perovskite film deposition method combining raster ultrasonic spray coating and chemical vapor deposition is reported. This method overcomes the coating size limitation of the existing stationary spray, single-pass spray, and spin-coating methods. In contrast with the spin-coating method (>90% Pb waste), negligible Pb waste during PbI2 deposition makes this method more environmentally friendly. Outstanding film uniformity across the entire area of 5 cm x 5 cm is confirmed by both large-area compatible characterization methods (electroluminescence and scattered light imaging) and local characterization methods (atomic force microscopy, scanning electron microscopy, photoluminescence mapping, UV-vis, and X-ray diffraction measurements on multiple sample locations), resulting in low solar cell performance decrease upon increasing device area. With the FAPb(I0.85Br0.15)(3) (FA = formamidinium) perovskite layer deposited by this method, champion solar modules show a power conversion efficiency of 14.7% on an active area of 12.0 cm(2) and an outstanding shelf stability (only 3.6% relative power conversion efficiency decay after 3600 h aging). Under continuous operation (1 sun light illumination, maximum power point condition, dry N-2 atmosphere with <5% relative humidity, no encapsulation), the devices show high light-soaking stability corresponding to an average T-80 lifetime of 535 h on the small-area solar cells and 388 h on the solar module.
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| 3. |
- Li, Ziyao, et al.
(författare)
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Atomic-level orbital coupling in a tri-metal alloy site enables highly efficient reversible oxygen electrocatalysis
- 2023
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 11:5, s. 2155-2167
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Tidskriftsartikel (refereegranskat)abstract
- Complex multi-metallic alloys with ultra-small sizes have received extensive attention in the fields of Zn-air battery and water splitting, because of their unique advantages including adjustable composition, tailorable active sites, and optimizable electronic structure. In this effort, an atomic-level orbital coupling strategy is presented to effectively regulate the electronic structures of ultra-small tri-metal Fe-Co-Ni nanoalloy particles confined in an N-doped carbon hollow nanobox. As expected, the optimal nanoalloy hybrid material exhibited notable bi-functional catalytic performances toward the oxygen reduction reaction (half-wave potential of 0.902 V) and oxygen evolution reaction (1.589 V at 10 mA cm−2) with a small ΔE of 0.687 V, exceeding the precious-metal-based and many previously reported catalysts. Furthermore, the as-assembled Zn-air device also displayed a superior specific capacity of 894 mA h g−1, a maximal power density of 247 mW cm−2, and impressive durability (over 100 hours). Ultraviolet photoelectron spectroscopy and density functional theory calculations revealed that the electronic structures could be finely tuned and optimized through ternary metal alloying, resulting in a suitable d-band center and advantageous interfacial charge-transfer, which in turn could effectively reduce the involved energy barriers in the electrocatalytic process and significantly boost its intrinsic activity of reversible oxygen catalysis. Thus, this work affords an effective method for the rational creation of bi-functional non-noble-metal-based electrocatalysts for sustainable energy technology.
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| 4. |
- Nie, Zhicheng, et al.
(författare)
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Tailoring the d-band center by intermetallic charge-transfer manipulation in bimetal alloy nanoparticle confined in N-doped carbon nanobox for efficient rechargeable Zn-air battery
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 463
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Tidskriftsartikel (refereegranskat)abstract
- In this effort, the electronic-structure modulation strategy through nano-alloying was rationally designed to fabricate Fe-Ni alloy particles embedded in an N-doped carbon nanobox. The as-developed catalyst outperformed the commercialized noble-metal benchmarks with a decent half-wave potential of 0.891 V for ORR and a small overpotential of 325 mV at 10 mA/cm2 for OER both in 0.1 M KOH solution. Beyond that, a highly-efficient regenerative Zn-air battery was also successfully constructed, evidenced by a small potential gap of 0.664 V (between Ej=10 and E1/2), a high specific capacity of 763 mAh/g, a large peak power density of 270 mW/cm2, and robust stability. Ultraviolet photoelectron spectroscopy and theoretical simulation confirmed that the alloying of Ni into Fe could well manipulate the electronic structure, leading to favorable intermetallic charge-transfer and then downshifting the d-band center of Fe adsorption sites, all of which help to significantly lower the reaction barriers of the involved intermediates during the electrocatalytic ORR/OER processes.
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| 5. |
- Nie, Zhicheng, et al.
(författare)
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Vacancy and doping engineering of Ni-based charge-buffer electrode for highly-efficient membrane-free and decoupled hydrogen/oxygen evolution
- 2023
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 642, s. 714-723
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Tidskriftsartikel (refereegranskat)abstract
- The realization of the membrane-free two-step water electrolysis is particularly important yet challenging for the low-cost and large-scale supply of hydrogen energy. In this effort, Co-doped Ni(OH)2 nanosheets were successfully anchored onto the nickel foam (NF) substrate through the in-situ growth of metal-organic frame material and the subsequent alkali-etching technique. Using the well-regulated Co-doping Ni(OH)2@NF electrodes as a charge mediator, electrochemical hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were decoupled on time scales, thus affording a membrane-free two-step route for H2 and O2 productions. In this architecture, the first HER process on the cathode could be maintained for 1300 s at a current of 100 mA, while the corresponding Ni(OH)2 charge mediator was simultaneously oxidized to NiOOH, with a decent cell voltage of 1.542 V. The subsequent OER process involved a reduction/regeneration of Ni(OH)2 (from NiOOH to Ni(OH)2) and an anodic O2-production, with an operating voltage of 0.291 V. Moreover, the Ni-Zn battery assembled through the combination of NiOOH and Zn sheet could replace the second step of OER to achieve the coupling of continuous H2-production and battery discharge, thus also providing a new way for hydrogen production without an external power supply. Experiment and theoretical calculations have shown that the cobalt-doping not only improved the conductivity of the charge-buffer electrode, but also shifted its redox potential cathodically and boosted the adsorption affinity of the buffer medium to OH– ions, both contributing to promoted HER and OER activity. Therefore, this decoupled water electrolysis device affords a promising pathway to support the efficient conversion of renewables to hydrogen.
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| 6. |
- Zhang, Lei, et al.
(författare)
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Nickel-induced charge redistribution in Ni-Fe/Fe3C@nitrogen-doped carbon nanocage as a robust Mott-Schottky bi-functional oxygen catalyst for rechargeable Zn-air battery
- 2022
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 625, s. 521-531
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Tidskriftsartikel (refereegranskat)abstract
- Designing earth-abundant and advanced bi-functional oxygen electrodes for efficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are extremely urgent but still ambiguous. Thus, metal-semiconductor nanohybrids were developed with functionally integrating ORR-active Ni species, OER-active Fe/Fe3C components, and multifunctional N-doped carbon (NDC) support. Expectantly, the resulted NDC nanocage embedded with Ni-Fe alloy and Fe3C particles, as assembled Mott-Schottky-typed catalyst, delivered a promoted half-wave potential of 0.904 V for ORR and a low overpotential of 315 mV at 10 mA/cm2 for OER both in alkaline media, outperforming those of commercial Pt/C and RuO2 counterparts. Most importantly, the optimized Ni-Fe/Fe3C@NDC sample also afforded a peak power density of 267.5 mW/cm2 with a specific capacity of 773.8 mAh/gZn and excellent durability over 80 h when used as the air electrode in rechargeable Zn-air batteries, superior to the state-of-the-art bi-functional catalysts. Ultraviolet photoelectron spectroscopy revealed that the introduction of Ni into the Fe/Fe3C@NDC component could well manipulate the electronic structure of the designed electrocatalyst, leading to an effective built-in electric field established by the Mott-Schottky heterojunction to expedite the continuous interfacial charge-transfer and thus significantly promote the utilization of electrocatalytic active sites. Therefore, this work provides an avenue for the designing and developing robust and durable Mott-Schottky-typed bi-functional catalysts for promising energy conversion.
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| 7. |
- Li, Jie, et al.
(författare)
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Introduction to the Special Section on Big Data and Artificial Intelligence for Network Technologies
- 2020
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Ingår i: IEEE Transactions on Network Science and Engineering. - : IEEE. - 2327-4697. ; 7:1, s. 1-2
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The papers in this special section examines the deployment of Big Data and artificial intelligence for network technologies. The eneration of huge amounts of data, called big data, is creating the need for efficient tools to manage those data. Artificial intelligence (AI) has become the powerful tool in dealing with big data with recent breakthroughs at multiple fronts in machine learning, including deep learning. Meanwhile, information networks are becoming larger and more complicated, generating a huge amount of runtime statistics data such as traffic load, resource usages. The emerging big data and AI technologies may include a bunch of new requirements, applications and scenarios such as e-health, Intelligent Transportation Systems (ITS), Industrial Internet of Things (IIoT), and smart cities in the term of computing networks. The big data and AI driven network technologies also provide an unprecedented patient to discover new features, to characterize user demands and system capabilities in network resource assignment, security and privacy, system architecture, modeling and applications, which needs more explorations. The focus of this special section is to address the big data and artificial intelligence for network technologies. We appreciate contributions to this special section and the valuable and extensive efforts of the reviewers. The topics of this special section range from big data and AI algorithms, models, architecture for networks and systems to network architecture.
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