Controllable synthesis of N-doped hollow, yolk-shell and solid carbon spheres via template-free method

Zhang, Lili; Liu, Lei; Li, Meng; Yu, Yan; Hu, Zepeng; Liu, Beibei; Lv, Haijun; Chen, Aibing

doi:10.1016/j.jallcom.2018.11.169

Cited by 23 publications

(6 citation statements)

References 54 publications

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“…Moreover, the energy densities of CSCS, YSCS, and HCS are 13.3, 16.8, and 25.2 Wh kg –1 at a specific power density of 1.596, 1.608, and 2.000 kW kg –1 , respectively. Meanwhile, the energy density of HCS is higher than those of other reported carbon materials, as shown in detail in Table S2. − The results demonstrated that HCS had a remarkable energy-power characteristic and is promising as a supercapacitor electrode material.…”

Section: Results and Discussionmentioning

confidence: 92%

Controlling the Inner Structure of Carbon Spheres via “Protective-Dissolution” Strategy for Supercapacitor

Zhang

Liu

et al. 2019

J. Phys. Chem. C

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Hollow, yolk−shell, and core−shell carbon spheres have attracted substantial attention, because of their unique structure and potential application in energy storage/ conversion. Unfortunately, the structural adjustment of the carbon sphere mostly depends on the template method with a tedious process, and most of the methods are not conductive to large-scale production. Furthermore, one particular structure requires one specific strategy. Here, the carbon spheres with hollow, yolk−shell, and core−shell structure are prepared via a facile and feasible "protective-dissolution" strategy. A suitable amount of acetone is used to dissolve the core of resorcinol-formaldehyde (RF) resin as an effective solvent, and also to regulate the structure as a critical controlling factor. The dissolved resin oligomer assembled outside of the undissolved RF resin sphere under the action of cetyltrimethylammonium (CTAB), forming a strong polymer shell which prevents the RF resin sphere from further dissolution in acetone. The obtained carbon sphere with the especially hollow structure shows a large cavity, high specific surface area, and excellent electrochemical performance with high capacitance of 272 F g −1 at 1 A g −1 , and the capacitance retention is 95.2% after 10 000 charge−discharge cycles at 5 A g −1 . These outstanding properties and remarkable performance make them potential as supercapacitor electrode materials.

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Section: Results and Discussionmentioning

confidence: 92%

Controlling the Inner Structure of Carbon Spheres via “Protective-Dissolution” Strategy for Supercapacitor

Zhang

Liu

et al. 2019

J. Phys. Chem. C

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“…Even though with 12 hours of mixing, the concentration of Fe 3+ ions in the outer layer and the core of M/G/H spheres are still different. The graphitization of the outer layer of M/G/H sphere is faster than that of the core, eventually hollow structure with holes is generated [36,37] . Therefore, the iron salt induction causes the formation of high nitrogen content microspheres into hollow structures [38] .…”

Section: Resultsmentioning

confidence: 99%

“…The graphitization of the outer layer of M/G/H sphere is faster than that of the core, eventually hollow structure with holes is generated. [36,37] Therefore, the iron salt induction causes the formation of high nitrogen content microspheres into hollow structures. [38] Fe atoms could also aggregate to form Fe nanocrystals, which subsequently convert to iron oxides and carbides at high temperature.…”

Section: Chemistryselectmentioning

confidence: 99%

Fe₃C Decorated N, Fe Co‐Doped Hollow Carbon Microspheres as Efficient Air Electrode Catalyst for Zinc‐Air Battery

Zhang

Sun

et al. 2022

ChemistrySelect

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Efficient metal‐air batteries need active catalysts with low cost for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, hollow spherical Fe−M/G/H catalyst was synthesized through a polycondensation/pyrolysis method without template. Polycondensation of melamine, d‐glucose, and hexamethylenetetramine was accomplished to obtain carbon spheres with high nitrogen content. Hollow microspheres containing Fe‐Nx and Fe3C were fabricated by subsequent pyrolysis with Fe catalysts. Hollow microsphere structures not only expose more active sites (doped‐N, Fe‐Nx, and Fe3C), but also promote the mass transfer of O2. Fe−M/G/H possesses superior ORR performance in alkaline media with high limiting current density (5.09 mA cm−2) and half‐wave potential (0.80 V). The OER activity of Fe−M/G/H is superior to commercial Pt/C. Fe−M/G/H assembled zinc‐air battery exhibits high peak power density (90.27 mW cm−2) and long stability. This research provides a new approach to design hollow carbon catalysts with homo‐dispersed Fe‐Nx/Fe3C active sites and high doped‐N concentration.

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“…The Cyclic Voltammetry (CV) curves of all NHCNCs at 5 mV s −1 (Fig. 5a) are quasi-rectangular, which can be explained by two different capacitances comprising the dominate electric double layer capacitance (EDLC) and the less faradaic pseudocapacitance derived from doping of heteroatoms 11 .…”

Section: Resultsmentioning

confidence: 99%

Biocompatible Mesoporous Hollow Carbon Nanocapsules for High Performance Supercapacitors

Wang

Liu

Bradley

et al. 2020

Sci Rep

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A facile and general method for the controllable synthesis of n-doped hollow mesoporous carbon nanocapsules (NHCNCs) with four different geometries has been developed. The spheres (NHCNC-1), low-concaves (NHCNC-2), semi-concaves (NHCNC-3) and wrinkles (NHCNC-4) shaped samples were prepared and systematically investigated to understand the structural effects of hollow particles on their supercapacitor performances. Compared with the other three different shaped samples (NHCNC-1, NHCNC-2, and NHCNC-4), the as-synthesized semi-concave structured NHCNC-3 demonstrated excellent performance with high gravimetric capacitance of 326 F g −1 (419 F cm −3 ) and ultra-stable cycling stability (96.6% after 5000 cycles). The outstanding performances achieved are attributed to the unique semi-concave structure, high specific surface area (1400 m 2 g −1 ), hierarchical porosity, high packing density (1.41 g cm −3 ) and high nitrogen (N) content (up to 3.73%) of the new materials. These carbon nanocapsules with tailorable structures and properties enable them as outstanding carriers and platforms for various emerging applications, such as nanoscale chemical reactors, catalysis, batteries, solar energy harvest, gas storage and so on. In addition, these novel carbons have negligible cytotoxicity and high biocompatibility for human cells, promising a wide range of bio applications, such as biomaterials, drug delivery, biomedicine, biotherapy and bioelectronic devices.Supercapacitors have drawn increasing attention due to their high power density, fast charge/discharge capability, long cycle life, low cost and environmental friendliness among various electrochemical energy storage devices 1 . Carbon materials are the most promising supercapacitor electrode materials, due to their high specific surface area, high electrical conductivity, tailorable pore structures and excellent chemical stability 2 . The pore structures and the surface properties of carbon materials have significant effects on the electrode performances 3 . In order to increase the volumetric capacitance of the electrode materials 4,5 , it is vital to optimize the morphology and reduce the void volume of the hollow porous carbon materials.Hollow carbon nanocapsules (HCNCs) are an interesting class of carbon materials, due to their unique properties such as high surface-to-volume ratio, low densities, large void space and high electrical conductivity 6,7 . The hollow macropore cavities and interior space of the HCNCs can act as anion-buffering reservoirs to shorten the diffusion distance of electrolyte ions 8 , while the mesopores and micropores in the shell can promote ion transport, minimize diffusion pathways from the electrolyte to the micropores, and increase the specific surface area to maximize the electric double layer capacitance 9 . For high-rate performances, HCNCs are particularly interesting as they have ultrahigh specific surface area, large surface-to-volume ratio, large void space along with an appropriate interconnected pore channels to facilitate ion ...

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Controllable synthesis of N-doped hollow, yolk-shell and solid carbon spheres via template-free method

Cited by 23 publications

References 54 publications

Controlling the Inner Structure of Carbon Spheres via “Protective-Dissolution” Strategy for Supercapacitor

Controlling the Inner Structure of Carbon Spheres via “Protective-Dissolution” Strategy for Supercapacitor

Fe₃C Decorated N, Fe Co‐Doped Hollow Carbon Microspheres as Efficient Air Electrode Catalyst for Zinc‐Air Battery

Biocompatible Mesoporous Hollow Carbon Nanocapsules for High Performance Supercapacitors

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Controllable synthesis of N-doped hollow, yolk-shell and solid carbon spheres via template-free method

Cited by 23 publications

References 54 publications

Controlling the Inner Structure of Carbon Spheres via “Protective-Dissolution” Strategy for Supercapacitor

Controlling the Inner Structure of Carbon Spheres via “Protective-Dissolution” Strategy for Supercapacitor

Fe3C Decorated N, Fe Co‐Doped Hollow Carbon Microspheres as Efficient Air Electrode Catalyst for Zinc‐Air Battery

Biocompatible Mesoporous Hollow Carbon Nanocapsules for High Performance Supercapacitors

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Fe₃C Decorated N, Fe Co‐Doped Hollow Carbon Microspheres as Efficient Air Electrode Catalyst for Zinc‐Air Battery