Nanostructured 3D zinc cobaltite/nitrogen-doped reduced graphene oxide composite electrode for supercapacitor applications

Sahoo, Sumanta,Shim, Jae-Jin THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2017 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.54 No.-

<P><B>Abstract</B></P> <P>This paper reports the electrochemical performance of a binder-free supercapacitor electrode based on ZnCo<SUB>2</SUB>O<SUB>4</SUB> nanoflakes and N-doped reduced graphene oxide (rGO). The morphology of ZnCo<SUB>2</SUB>O<SUB>4</SUB> was tailored by changing the substrate from bare Ni foam (NiF) to rGO-supported NiF and then to N-doped rGO-supported NiF. The N-doped electrode exhibited superior electrochemical performance, i.e., high specific capacitance (1613Fg<SUP>−1</SUP> at 1Ag<SUP>−1</SUP>) and excellent cycling stability (97.3% after 5000 cycles). An asymmetric supercapacitor based on this nanohybrid exhibited a high energy density of 36.5Whkg<SUP>−1</SUP>. This excellent electrochemical performance highlights the potential of this electrode for next-generation supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A 3D nanohybrid composite ZnCo<SUB>2</SUB>O<SUB>4</SUB>/N-doped reduced graphene oxide on nickel foam was fabricated by hydrothermal method. </LI> <LI> The ZNGN 3D nanohybrid composite exhibited a high specific capacitance of 1613Fg<SUP>−1</SUP> at a 1Ag<SUP>−1</SUP> current density. </LI> <LI> The ZNGN 3D nanohybrid composite showed excellent capacitance retention of 97.3% after 5000 cycles. </LI> <LI> A ZNGN based asymmetric device delivered a high energy density of 36.5Whkg<SUP>−1</SUP> and a high power density of 6968Wkg<SUP>−1</SUP>. </LI> <LI> The ZNGN 3D nanohybrid composite can be successfully applied to supercapacitor applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Fundamentals of Fascinating Graphene Nanosheets: A Comprehensive Study

Sumanta Kumar Sahoo,Archana Mallik 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

Graphene nanosheets have attracted immense research interest among the materials science community from electronics to the biomedical field. Being the first member of two-dimensional nanomaterials family, discovered in 2004 followed by the Nobel Prize winning in 2010, it is now readily witnessing global industrial revolutions. The nanomaterial is bestowed with such unprecedented features that can be tangible to a wide spectrum of applications ranging from energy storage devices to sensor application. Enormous flattened surfaces, superior mechanical strength and flexibility, ballistic intrinsic carrier mobility, nearly transparent nature, high thermal conductivity and room-temperature ferromagnetic behavior are few of the extraordinary attributes of the monolayer of carbon nanosheets. In this comprehensive review, an attempt has been put forward to precisely revisit and represent the literature available on the fundamental properties of graphene nanomaterials. Also, the usage of its characteristic features in various applications as well as synthesis process has been briefly discussed.

Morphological Dependence of Field Emission Properties of Silicon Nanowire Arrays

Sumanta Kumar Sahoo,Arumugam Marikani 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.2

The electron field emission (EFE) properties of vertically aligned arrays of silicon nanowires (SiNWs) grown from silicon substrate at different gold sputtering periods of 0 s, 8 s, 15 s and 25 s at a rate of 10 nm/min by electroless metal deposition process were investigated. It has been observed that the transformation of silicon tips from irregular to highly dense and uniform cylindrical morphological nanostructures with an increase in Au sputtering periods. A significant enhancement in EFE properties of as-prepared arrays of SiNWs with the increase in Au sputtering periods is observed. The threshold fields for attaining current density of 0.1 mA cm-2 were decreased gradually as 32.38 Vµm-1, 29.37 Vµm-1 and 23.19 Vµm-1 for the arrays of SiNWs synthesized from Si substrate by Au coating of 8 s, 15 s and 25 s respectively. Moreover, from Fowler–Nordheim plot, the turn-on field is observed to decrease from 16.56 V/µm for as-prepared to 8.77 V/µm for 25 s Au sputtered SiNW arrays. The effective work functions of the electron emitting array of SiNWs have been improved from 0.5 meV to 0.1 meV.

Mesoporous Fe–Ni–Co ternary oxide nanoflake arrays on Ni foam for high-performance supercapacitor applications

Sahoo, Sumanta,Nguyen, Thi Toan,Shim, Jae-Jin Elsevier 2018 Journal of industrial and engineering chemistry Vol.63 No.-

<P><B>Abstract</B></P> <P>A new 3D binder-free ternary Fe–Ni–Co oxide nanoflake arrays on Ni foam was synthesized using a simple facile two-step process. The as-prepared supercapacitor electrode showed excellent electrochemical performance, such as a high specific capacitance of 867Fg<SUP>−1</SUP> and excellent cycling stability (92.3% capacitance retention after 10,000 charge–discharge cycles). In addition, an aqueous hybrid asymmetric supercapacitor device based on this material exhibited high energy density of 40Whkg<SUP>−1</SUP> and excellent capacitance retention of 87.4% after 5000 cycles. This outstanding electrochemical performance highlights the potential of this 3D mesoporous ternary mixed-metal oxide electrode in commercial high performance supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A mesoporous 3D binder-free ternary Fe–Ni–Co oxide (FNCN) was prepared. </LI> <LI> FNCN exhibited a specific capacitance of 867Fg<SUP>−1</SUP> at a current density of 3Ag<SUP>−1</SUP>. </LI> <LI> The electrode exhibited excellent capacitance retention of 92.3% after 10,000 cycles. </LI> <LI> The FNCN-based aqueous device exhibited a high energy density of 40Whkg<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Simple, Fast and Cost-Effective Electrochemical Synthesis of Few Layer Graphene Nanosheets

Sumanta Kumar Sahoo,Archana Mallik 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.2

"We report an effcient and green approach for mass production of few layered graphene nanosheets (FLGNSs) by intercalation and exfoliation of pyrolytic graphite sheet in a simple protic, H2SO4 electrolyte. The as-prepared FLGNSs at the optimum intercalate concentration of 0.5M H2SO4 is able to produce large domain of lateral dimension of 11–26µm consisting of 4–6 stacked graphene layers, as confirmed by field emission scanning electron microscopy and atomic force microscopy, respectively. Surface oxygenation and a characteristic absorbance peak at 228nm are well observed for electrochemical exfoliated FLGNSs from Fourier transform infrared spectroscopy and UV–Vis spectra respectively. (002) planes of the obtained graphene sheets have been confirmed from X-ray diffraction pattern. The characteristic Raman bands have been observed at 1354 cm-1 and 1590 cm-1 in the exfoliated FLGNSs. "

Modified Graphene/Polyaniline Nanocomposites for Supercapacitor Application

Sumanta Sahoo,Chapal Kumar Das,G. Karthikeyan,G. C. Nayak 한국고분자학회 2012 Macromolecular Research Vol.20 No.4

This work explored the effect of graphene surface modification on the electrochemical performance of polyaniline-based nanocomposite. The surface modification of graphene was confirmed by Fourier transform infrared spectroscopy. Field emission scanning electron microscopy and high-resolution transmission electron microscopy showed uniform polyaniline coating of the modified graphene. The specific capacitance of the graphene/polyaniline composite was 242 F/g, but it decreased to 193 F/g after graphene modification. However, the capacitance retention increased from 86% to 89% after 500 cycles due to the graphene modification. The thermal stability of the composite also increased after the graphene modification.

Highly Uniform Atomic Layer-Deposited MoS₂@3D-Ni-Foam: A Novel Approach To Prepare an Electrode for Supercapacitors

Nandi, Dip K.,Sahoo, Sumanta,Sinha, Soumyadeep,Yeo, Seungmin,Kim, Hyungjun,Bulakhe, Ravindra N.,Heo, Jaeyeong,Shim, Jae-Jin,Kim, Soo-Hyun American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.46

<P>This article takes an effort to establish the potential of atomic layer deposition (ALD) technique toward the field of supercapacitors by preparing molybdenum disulfide (MoS2) as its electrode. 'While molybdenum hexacarbonyl [Mo(CO)(6)] serves as a novel precursor toward the low temperature 'synthesis of ALD-grown MoS2, H2S plasma helps to deposit its polycrystalline phase at 200 degrees C. Several ex situ characterizations such as X-ray diffractometry (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and so forth are performed in detail to study the as-grown MoS2 film on a Si/SiO2 substrate. While stoichiometric MoS2 with very negligible amount of C and O impurities was evident from XPS, the XRD and high-resolution transmission electron microscopy analyses confirmed the (002)-oriented polycrystalline h-MoS2 phase of the as-grown film. A comparative study of ALD-grown MoS2 as a supercapacitor electrode on 2-dimensional stainless steel and on 3-dimensional (3D) Ni-foam substrates clearly reflects the advantage and the potential of ALD for growing a uniform and conformal electrode material on a 3D-scaffold layer. Cyclic voltammetry measurements showed both double-layer capacitance and capacitance contributed by the faradic reaction at the MoS2 electrode surface. The optimum number of ALD cycles was also found out for achieving maximum capacitance for such a MoS2@3D-Ni-foam electrode. A record high areal capacitance of 3400 mF/cm(2) was achieved for MoS2@3D-Ni-foam grown by 400 ALD cycles at a current density of 3 mA/cm(2). Moreover, the ALD-grown MoS2@3D-Ni-foam composite also retains high areal capacitance, even up to a high current density of 50 mA/cm(2). Finally, this directly grown MoS2 electrode on 3D-Ni-foam by ALD shows high cyclic stability (>80%) over 4500 charge discharge cycles which must invoke the research community to further explore the potential of ALD for such applications.</P>

Low temperature atomic layer deposited molybdenum nitride-Ni-foam composite: An electrode for efficient charge storage

Nandi, Dip K.,Sahoo, Sumanta,Kim, Tae Hyun,Cheon, Taehoon,Sinha, Soumyadeep,Rahul, Ramesh,Jang, Yujin,Bae, Jong-Seong,Heo, Jaeyeong,Shim, Jae-Jin,Kim, Soo-Hyun Elsevier 2018 Electrochemistry communications Vol.93 No.-

<P><B>Abstract</B></P> <P>Molybdenum nitride (MoN<SUB>x</SUB>) was directly grown on 3-dimensional Ni-foam (NF) at relatively low temperature of 250 °C by atomic layer deposition (ALD) and then tested as an electrode for charge storage. The successful formation of MoN<SUB>x</SUB>@NF composite was confirmed by several characterization techniques. The scanning and transmission electron microscopy analyses showed the extremely uniform and conformal coating of the MoN<SUB>x</SUB> on NF. The presence of NF influenced the redox-reactions in the composite and established the composite as a potential electrode for efficient charge-storage. High areal capacity (geometrical) of 130 mC/cm<SUP>2</SUP> was achieved at a current density of 2 mA/cm<SUP>2</SUP>. The excellent cyclic stability reflected the conducting nature of the composite.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Low temperature ALD-grown MoN<SUB>x</SUB> on 3D Ni-foam is tested as a charge-storage electrode. </LI> <LI> The uniform and conformal growth of MoN<SUB>x</SUB> on Ni-foam is confirmed. </LI> <LI> High areal capacity (130 mC/cm<SUP>2</SUP>) is achieved with >100% capacity retention. </LI> <LI> The robustness of the MoN<SUB>x</SUB>@Ni-foam composite is revealed by post-cycling analysis. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Poly(aniline‑<i>co</i>‑pyrrole)-spaced graphene aerogel for advanced supercapacitor electrodes

Tran, Van Chinh,Sahoo, Sumanta,Hwang, Jinho,Nguyen, Van Quang,Shim, Jae-Jin Elsevier S.A 2018 Journal of Electroanalytical Chemistry Vol.810 No.-

<P><B>Abstract</B></P> <P>Polyaniline (PANI) and polypyrrole (PPy) are conducting polymers used widely in Supercapacitor applications because of their facile synthesis, low cost, and good pseudo-capacitive performance. In this study, PANI and PPy were combined with reduced graphene oxide (RGO) to form a new 3D hybrid aerogel, poly(aniline‑co‑pyrrole)/graphene aerogel (PGA), which was assessed as a promising material for supercapacitor electrodes. A one-step hydrothermal co-assembly method was adopted to synthesize the active electrode materials. The PGA exhibited a high specific capacitance of 675F/g at a current density of 0.5A/g with excellent cycling stability (97.5% capacitance retention and near 100% coulombic efficiency after 1000charge/discharge cycles).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Poly(aniline-co-pyrrole)-spaced graphene aerogel (PGA) was prepared. </LI> <LI> PGA exhibited a highly porous nanoarchitecture. </LI> <LI> PGA achieved a good specific capacitance of 675F/g at a density of 0.5A/g. </LI> <LI> PGA showed a good stability (97.5% capacitance retention after 1000cycles). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Room-temperature synthesis of NiS hollow spheres on nickel foam for high-performance supercapacitor electrodes

Tran, Van Chinh,Sahoo, Sumanta,Shim, Jae-Jin North-Holland 2018 Materials letters Vol.210 No.-

<P><B>Abstract</B></P> <P>NiS hollow spheres were synthesized directly on the surface of Ni foam (NiS@NF) at room temperature via a simple electrodeposition in a KOH/thiourea solution without any Ni precursors. Morphological analysis revealed the formation of NiS hollow spheres, which consisted of nanoparticles. The NiS@NF nanocomposite exhibited a very high specific capacitance of 1553Fg<SUP>−1</SUP> (2.64Fcm<SUP>−2</SUP>) at a current density of 2.35Ag<SUP>−1</SUP> (4mAcm<SUP>−2</SUP>) in 6M KOH electrolyte. The NiS@NF nanocomposite also demonstrated excellent cycling stability (95.7% specific capacitance retention after 2000 cycles).</P> <P><B>Highlights</B></P> <P> <UL> <LI> NiS hollow spheres were electrodeposited directly on Ni foam at room temperature. </LI> <LI> The NiS@NF composite showed high specific capacitance: 1553Fg<SUP>−1</SUP> at 2.35Ag<SUP>−1</SUP>. </LI> <LI> The NiS@NF composite exhibited good cycling stability: 95.7% after 2000 cycles. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>