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- Huang, Shoushuang, et al.
(författare)
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Amorphous and defective Co-P-O@NC ball-in-ball hollow structure for highly efficient electrocatalytic overall water splitting
- 2023
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Ingår i: Journal of Colloid and Interface Science. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0021-9797 .- 1095-7103. ; 649, s. 1047-1059
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical water splitting using hollow and defect-rich catalysts has emerged as a promising strategy for efficient hydrogen production. However, the rational design and controllable synthesis of such catalysts with intricate morphology and composition present significant challenges. Herein, we propose a template-engaged approach to fabricate a novel ball-in-ball hollow structure of Co-P-O@N-doped carbon with abundant oxygen vacancies. The synthesis process involves the preparation of uniform cobalt-glycerate (Co-gly) polymer microspheres as precursors, followed by surface coating with ZIF-67 layer, adjustable chemical etching by phytic acid, and controllable pyrolysis at high temperature. The resulting ball-in-ball structure offers a large number of accessible active sites and high redox reaction centers, facilitating efficient charge transport, mass transfer, and gas evolution, which are beneficial for the acceleration of electrocatalytic reaction. Additionally, density functional theory (DFT) calculations indicate that the incorporation of oxygen and the presence of Co-P dangling bonds in CoP significantly enhance the adsorption of oxygenated species, leading to improved intrinsic electroactivity at the single-site level. As a sequence, the titled catalyst exhibits remarkable electrocatalytic activity and stability for water splitting in alkaline media. Notably, it only requires a low overpotential of 283 mV to achieve a current density of 10 mA cm-2 for the oxygen evolution reaction. This work may provide some new insights into the design of complex hollow structures of phosphides with abundant defects for energy conversion.
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| 2. |
- Zhang, Lingchao, et al.
(författare)
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Intersperse copper nanoparticles into 3D fibrous silica-supported carbon spheres for electrocatalytic nitrogen reduction
- 2022
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Ingår i: Journal of Alloys and Compounds. - : Elsevier Science SA. - 0925-8388 .- 1873-4669. ; 910
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Tidskriftsartikel (refereegranskat)abstract
- The electrocatalysts are critical to the electrocatalytic nitrogen reduction reaction (e-NRR) technique and its development. Herein, through morphological structure modulation, three-dimensional (3D) fibrous silica nanospheres (KCC-1) are firstly fabricated as the supporting scaffold, followed by the coating of nitrogendoped carbon and interspersing of copper nanoparticles. The resulting carbon spheres (KNC) has very uniform interspersion of copper nanoparticles (Cu-NPs) in the 3D fibrous structure ensuring high accessible active sites for nitrogen molecules; the thin surface carbon layer offering a rich channel for electron transport; and nitrogen dopant allowing efficient electron transfer of copper atoms throng metal-nitrogen covalent bonds. When used as electrocatalysts to e-NRR, KNC exhibits good electrochemical activity, selectivity, and good stability, and can obtain an ammonia yield of approximately 6.67 mu g h-1 mgcat-1 and an excellent Faraday efficiency (FE) of 8.1% in 0.1 M sodium sulfate solution at - 0.4 V (vs. RHE).
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