| 1. |
- Li, Luhan, et al.
(författare)
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Tailoring charge reconfiguration in dodecahedral Co2P@carbon nanohybrids by triple-doping engineering for promoted reversible oxygen catalysis
- 2022
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 10:40, s. 21659-21671
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Tidskriftsartikel (refereegranskat)abstract
- Simultaneously tuning the electronic structure of active sites and the microenvironment of the carbon matrix in metal phosphide/carbon nanohybrids is the most effective way to design and develop bi-functional electrocatalysts for electrochemically related energy storage devices. Inspired by this, a robust and advanced N/P co-doped carbon-based dodecahedron catalyst with confined Fe-doped Co2P particles was successfully prepared through a multi-doping engineering strategy. Phytic acid molecules, which were used in the synthesis of the catalyst, not only contribute to the formation of the porous structure, but also act as a phosphorus source to form the corresponding metal phosphide and the P dopant in the carbon matrix. Thanks to the unique composition and structure-dependent merits, the microenvironment of the electrocatalyst was significantly modulated, thus promoting the advantageous local charge rearrangement and smooth mass/charge transfer processes during the oxygen-related electrocatalytic reactions. As a result, the resultant catalyst exhibited significantly enhanced reversible oxygen activity, as evidenced by an ultra-small potential gap of 0.655 V (half-wave potential of 0.895 V for the oxygen reduction reaction; η10 of 320 mV for the oxygen evolution reaction), a remarkable specific capacity of 762 mA h gZn−1, and high voltaic efficiency, exceeding most previous reports. This study provides a new synthetic approach for fabricating highly efficient bi-functional oxygen catalysts and can be handily extended to the synthesis of other heterogeneous electrocatalysts for sustainable energy storage.
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| 2. |
- Ye, Ying, et al.
(författare)
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Simultaneously promoting charge and mass transports in carved particle-in-box nanoreactor for rechargeable Zn-air battery
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 446
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Tidskriftsartikel (refereegranskat)abstract
- Fundamental understanding of fabricating promoted bi-functional electrocatalyst to achieve fast charge-transfer and smooth mass-transport in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) through the rational management of catalyst composition and ingenious design of nanostructure is highly desired but still a formidable challenge. Herein, an advanced carved particle-in-box nanoreactor, composed of small Fe-Co-Ni tri-metallic alloy nanoparticles confined in porous nitrogen-doped carbon nanocage, was developed through a spatially-confined pyrolysis strategy. Tri-metal alloy could optimize the electronic structure of the catalyst, thus inducing the charge redistribution, and then regulating the adsorption and desorption energy barriers of intermediates in electrochemical reactions. Unique nano-hole design provided convenient and efficient channels for mass transfer during ORR and OER processes. Thanks to these attributes, the hybrid electrocatalyst delivered decent reversible oxygen catalytic activities, evidenced by a high half-wave potential of 0.850 V towards ORR and a low overpotential of 355 mV at 10 mA/cm2 for OER both in alkaline electrolyte. As a proof-of-concept, this as-developed carved particle-in-box nanoreactor enabled the assembled Zn-air battery to deliver a narrow potential gap of 0.735 V, a decent power density of 315 mW/cm2, a notable specific capacity of 754 mAh/gZn and excellent durability up to 165 h of continuous charge and discharge operations, thus implying the potential applications of this sophisticated catalyst model for promising energy conversion.
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| 3. |
- 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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