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Phase-controlled synthesis of α-NiS nanoparticles confined in carbon nanorods for high performance supercapacitors.

Sun C, Ma M, Yang J, Zhang Y, Chen P, Huang W, Dong X - Sci Rep (2014)

Bottom Line: A facile and phase-controlled synthesis of α-NiS nanoparticles (NPs) embedded in carbon nanorods (CRs) is reported by in-situ sulfurating the preformed Ni/CRs.The nanopore confinement by the carbon matrix is essential for the formation of α-NiS and preventing its transition to β-phase, which is in strong contrast to large aggregated β-NiS particles grown freely without the confinement of CRs.While the high electrochemical stability (approximately 100% retention of specific capacitance after 2000 charge/discharge cycles) is attributed to the supercapacitor-battery electrode, which makes synergistic effect of capacitor (CRs) and battery (NiS NPs) components rather than a merely additive composite.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Flexible Electronics (KLOFE) &Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), 30 South Puzhu Road, Nanjing 211816, P. R. China.

ABSTRACT
A facile and phase-controlled synthesis of α-NiS nanoparticles (NPs) embedded in carbon nanorods (CRs) is reported by in-situ sulfurating the preformed Ni/CRs. The nanopore confinement by the carbon matrix is essential for the formation of α-NiS and preventing its transition to β-phase, which is in strong contrast to large aggregated β-NiS particles grown freely without the confinement of CRs. When used as electrochemical electrode, the hybrid electrochemical charge storage of the ultrasmall α-NiS nanoparticels dispersed in CRs is benefit for the high capacitor (1092, 946, 835, 740 F g(-1) at current densities of 1, 2, 5, 10 A g(-1), respectively.). While the high electrochemical stability (approximately 100% retention of specific capacitance after 2000 charge/discharge cycles) is attributed to the supercapacitor-battery electrode, which makes synergistic effect of capacitor (CRs) and battery (NiS NPs) components rather than a merely additive composite. This work not only suggests a general approach for phase-controlled synthesis of nickel sulfide but also opens the door to the rational design and fabrication of novel nickel-based/carbon hybrid supercapacitor-battery electrode materials.

No MeSH data available.


Related in: MedlinePlus

Schematic illustration for the synthesis of α and β-NiS/CRs composites.
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f1: Schematic illustration for the synthesis of α and β-NiS/CRs composites.

Mentions: As illustrated in Fig. 1, α-NiS/CRs composites were exclusively synthesized when Ni/CRs were directly in-situ sulfurated by refluxing in glycerol for 1 h. In comparison, sulfuration of the mixture of Ni NPs and mesoporous CRs (MCRs) leads to formation of β-NiS/CRs composite. MCRs were produced by removing Ni NPs from Ni/CRs via overnight incubation with 3 M HCl. The microstructure of α-NiS/CRs composite was characterized by SEM and TEM which was show in Fig. 2a–2d As revealed by field-emission scanning electron microscopy (FESEM), CRs are decorated with numerous α-NiS NPs after in-situ sulfidation (Fig. 2a). EDS microanalysis indicates that the atomic ratio of Ni/S (12.8/13.1) is closed to the stoichiometry of NiS (Fig. S2). The unaltered C/Ni ratio before and after sulfidation suggests an in-situ nucleation process. Transmission electron microscopy (TEM) shows that α-NiS NPs (black dots) with uniform particle size (~5 nm) are homogenously and densely embedded in the CRs (gray matrix) (Fig. 2b). As reported by previous literatures, the CRs coating can not only partially act as a conductive binder to increase the contact between nanoparticles but also alleviate the aggregation of the active materials and lead to the excellent electrochemical cycling stability3132. High-resolution transmission electron microscopy (HRTEM) in Fig. 2c shows that the d-spacing of the NPs is 0.198 nm, which is in agreement with the d102-spacing of α-NiS (highlighted by dash circles). Uniform dispersion of NiS NPs in the carbon matrix is further confirmed by EDS mapping (Fig. 2d).


Phase-controlled synthesis of α-NiS nanoparticles confined in carbon nanorods for high performance supercapacitors.

Sun C, Ma M, Yang J, Zhang Y, Chen P, Huang W, Dong X - Sci Rep (2014)

Schematic illustration for the synthesis of α and β-NiS/CRs composites.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231331&req=5

f1: Schematic illustration for the synthesis of α and β-NiS/CRs composites.
Mentions: As illustrated in Fig. 1, α-NiS/CRs composites were exclusively synthesized when Ni/CRs were directly in-situ sulfurated by refluxing in glycerol for 1 h. In comparison, sulfuration of the mixture of Ni NPs and mesoporous CRs (MCRs) leads to formation of β-NiS/CRs composite. MCRs were produced by removing Ni NPs from Ni/CRs via overnight incubation with 3 M HCl. The microstructure of α-NiS/CRs composite was characterized by SEM and TEM which was show in Fig. 2a–2d As revealed by field-emission scanning electron microscopy (FESEM), CRs are decorated with numerous α-NiS NPs after in-situ sulfidation (Fig. 2a). EDS microanalysis indicates that the atomic ratio of Ni/S (12.8/13.1) is closed to the stoichiometry of NiS (Fig. S2). The unaltered C/Ni ratio before and after sulfidation suggests an in-situ nucleation process. Transmission electron microscopy (TEM) shows that α-NiS NPs (black dots) with uniform particle size (~5 nm) are homogenously and densely embedded in the CRs (gray matrix) (Fig. 2b). As reported by previous literatures, the CRs coating can not only partially act as a conductive binder to increase the contact between nanoparticles but also alleviate the aggregation of the active materials and lead to the excellent electrochemical cycling stability3132. High-resolution transmission electron microscopy (HRTEM) in Fig. 2c shows that the d-spacing of the NPs is 0.198 nm, which is in agreement with the d102-spacing of α-NiS (highlighted by dash circles). Uniform dispersion of NiS NPs in the carbon matrix is further confirmed by EDS mapping (Fig. 2d).

Bottom Line: A facile and phase-controlled synthesis of α-NiS nanoparticles (NPs) embedded in carbon nanorods (CRs) is reported by in-situ sulfurating the preformed Ni/CRs.The nanopore confinement by the carbon matrix is essential for the formation of α-NiS and preventing its transition to β-phase, which is in strong contrast to large aggregated β-NiS particles grown freely without the confinement of CRs.While the high electrochemical stability (approximately 100% retention of specific capacitance after 2000 charge/discharge cycles) is attributed to the supercapacitor-battery electrode, which makes synergistic effect of capacitor (CRs) and battery (NiS NPs) components rather than a merely additive composite.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Flexible Electronics (KLOFE) &Institute of Advanced Materials (IAM), Jiangsu National Synergistic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University (Nanjing Tech), 30 South Puzhu Road, Nanjing 211816, P. R. China.

ABSTRACT
A facile and phase-controlled synthesis of α-NiS nanoparticles (NPs) embedded in carbon nanorods (CRs) is reported by in-situ sulfurating the preformed Ni/CRs. The nanopore confinement by the carbon matrix is essential for the formation of α-NiS and preventing its transition to β-phase, which is in strong contrast to large aggregated β-NiS particles grown freely without the confinement of CRs. When used as electrochemical electrode, the hybrid electrochemical charge storage of the ultrasmall α-NiS nanoparticels dispersed in CRs is benefit for the high capacitor (1092, 946, 835, 740 F g(-1) at current densities of 1, 2, 5, 10 A g(-1), respectively.). While the high electrochemical stability (approximately 100% retention of specific capacitance after 2000 charge/discharge cycles) is attributed to the supercapacitor-battery electrode, which makes synergistic effect of capacitor (CRs) and battery (NiS NPs) components rather than a merely additive composite. This work not only suggests a general approach for phase-controlled synthesis of nickel sulfide but also opens the door to the rational design and fabrication of novel nickel-based/carbon hybrid supercapacitor-battery electrode materials.

No MeSH data available.


Related in: MedlinePlus