Development of Cobalt Sulfide-graphene Composite for Supercapacitor Applications

( Milan Jana ),( Pranab Samanta ),( Naresh Chandra Murmu ),( Nam Hoon Kim ),( Tapas Kuila ),( Joong Hee Lee ) 한국복합재료학회 2016 Composites research Vol.29 No.4

Co₉S₈/reduced graphene (CSRG) has been prepared by a facile two step hydrothermal method and used as a supercapacitor electrode material. It is anticipated that the Co₉S₈ and reduced graphene oxide (RGO) would serve as a spacer material to each other to stop the agglomeration and simultaneous contribution of electrical double layer capacitance (RGO) and pseudocapacitance (Co₉S₈) would provide high electrochemical properties. The chemical analysis has been done by Fourier transform infrared spectroscopy and the morphology is characterised by field emission scanning electron microscopy. CSRG shows a high electrical conductivity of 98 S m^-1. The symmetric supercapacitor shows a specific capacitance of ~728 F g^-1 with a current density of 2 A g^-1. CSRG also showed an energy density of 25.2 Wh kg^-1 with a power density of 1000 W kg^-1.

Electrochemical functionalization and in-situ deposition of the SAA@rGO/h-BN@Ni electrode for supercapacitor applications

Sanjit Saha,Pranab Samanta,Naresh C. Murmu,김남훈,Tapas Kuila,이중희 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.52 No.-

Functionalization and electrodeposition of reduced graphene oxide/hexagonal boron nitride (rGO/h-BN)superlattice was carried out by a novel one-step electrochemical process. The sulfanilic acidazochromotrop (SAA) functionalized and electrodeposited nickel foam (SAA@rGO/h-BN@Ni) electrodeshowed high specific capacitance of1300 F g 1. An asymmetric supercapacitor cell (ASC) usingSAA@rGO/h-BN@Ni as positive and thermally reduced GO as negative electrode showed80%capacitance retention after 10,000 charge–discharge cycles. The ASC showed low relaxation timeconstant of0.47 ms along with high energy density ( 95.3 W h kg 1) and power density ( 7200 Wkg 1) ensuring the utility of SAA@rGO/h-BN@Ni electrode for supercapacitor application.

Electrochemical functionalization and in-situ deposition of the SAA@rGO/h-BN@Ni electrode for supercapacitor applications

Saha, Sanjit,Samanta, Pranab,Murmu, Naresh C.,Kim, Nam H.,Kuila, Tapas,Lee, Joong H. THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2017 Journal of Industrial and Engineering Chemistry Vol.52 No.-

<P><B>Abstract</B></P> <P>Functionalization and electrodeposition of reduced graphene oxide/hexagonal boron nitride (rGO/h-BN) superlattice was carried out by a novel one-step electrochemical process. The sulfanilic acid azochromotrop (SAA) functionalized and electrodeposited nickel foam (SAA@rGO/h-BN@Ni) electrode showed high specific capacitance of ∼1300Fg<SUP>−1</SUP>. An asymmetric supercapacitor cell (ASC) using SAA@rGO/h-BN@Ni as positive and thermally reduced GO as negative electrode showed ∼80% capacitance retention after 10,000 charge–discharge cycles. The ASC showed low relaxation time constant of ∼0.47ms along with high energy density (∼95.3Whkg<SUP>−1</SUP>) and power density (∼7200Wkg<SUP>−1</SUP>) ensuring the utility of SAA@rGO/h-BN@Ni electrode for supercapacitor application.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Enhanced Mechanical Properties of Functionalized Graphene Oxide/linear Low Density Polyethylene Composites Prepared by Melt Mixing

( Suman Chhetri ),( Pranab Samanta ),( Naresh Chandra Murmu ),( Tapas Kuila ),( Joong Hee Lee ) 한국복합재료학회 2016 Composites research Vol.29 No.4

Graphene oxide (GO) was concurrently reduced and functionalized using long alkyl chain dodecyl amine (DA). The DA functionalized GO (DA-G) was assumed to disperse homogenously in linear low density polyethylene (LLDPE). Subsequently, DA-G was used to fabricate DA-G/LLDPE composites by melt mixing technique. Fourier transform infrared spectra analysis was performed to ascertain the simultaneous reduction and functionlization of GO. Field emission scanning electron microscopy analysis was performed to ensure the homogenous distribution and dispersion of DA-G in LLDPE matrix. The enhanced storage modulus value of the composites validates the homogenous dispersion of DA-G and its good interfacial interaction with LLDPE matrix. An increased in tensile strength value by ~ 64% also confirms the generation of good interface between the two constituents, through which efficient load transfer is possible. However, no significant improvement in glass transition temperature was observed. This simple technique of fabricating LLDPE composites following industrially viable melt mixing procedure could be realizable to developed mechanically strong graphene based LLDPE composites for future applications.

A successive ionic layer adsorption and reaction (SILAR) method to fabricate a layer-by-layer (LbL) MnO₂-reduced graphene oxide assembly for supercapacitor application

Jana, Milan,Saha, Sanjit,Samanta, Pranab,Murmu, Naresh Chandra,Kim, Nam Hoon,Kuila, Tapas,Lee, Joong Hee Elsevier 2017 Journal of Power Sources Vol.340 No.-

<P><B>Abstract</B></P> <P>A facile, cost effective and additive-free successive ionic layer adsorption and reaction (SILAR) technique is demonstrated to develop layer-by-layer (LbL) assembly of reduced graphene oxide (RGO) and MnO<SUB>2</SUB> (MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB>) on a stainless steel current collector, for designing light-weight and small size supercapacitor electrode. The transmission electron microscopy and field emission scanning electron microscopy images shows uniform distribution of RGO and MnO<SUB>2</SUB> in the MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB>. The LbL (MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB>) demonstrates improved physical and electrochemical properties over the hydrothermally prepared MnO<SUB>2</SUB>-RGO (MnO<SUB>2</SUB>-RGO<SUB>Hydro</SUB>). The electrochemical environment of MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB> is explained by constant phase element in the high frequency region, and a Warburg element in the low frequency region in the Z-View fitted Nyquist plot. The equivalent circuit of the MnO<SUB>2</SUB>-RGO<SUB>Hydro</SUB>, displays the co-existence of EDL and constant phase element, indicating inhomogeneous distribution of MnO<SUB>2</SUB> and RGO by the hydrothermal technique. An asymmetric supercapacitor device is designed with MnO<SUB>2</SUB>-RGO<SUB>SILAR</SUB> as positive electrode, and thermally reduced GO (TRGO) as negative electrode. The designed cell exhibits high energy density of ∼88 Wh kg<SUP>−1</SUP>, elevated power density of ∼23,200 W kg<SUP>−1</SUP>, and ∼79% retention in capacitance after 10,000 charge-discharge cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Layer-by-layer assembly (LbL) of MnO<SUB>2</SUB> and reduced graphene oxide (RGO) is prepared. </LI> <LI> The LbL acts as single material with hybrid electrochemical properties. </LI> <LI> Uniform distribution of MnO<SUB>2</SUB> over RGO exhibits high specific capacitance. </LI> <LI> No organic binder is used to design the supercapacitor electrodes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>The LbL RGO-MnO<SUB>2</SUB> acts as single hybrid electro-active material and the hydrothermally prepared RGO-MnO<SUB>2</SUB> provides mixed properties of two materials.</P> <P>[DISPLAY OMISSION]</P>

Self Charging Sulfanilic Acid Azocromotrop/Reduced Graphene Oxide Decorated Nickel Oxide/Iron Oxide Solar Supercapacitor for Energy Storage Application

( Sanjit Saha ),( Milan Jana ),( Pranab Samanta ),( Naresh Chandra Murmu ),( Joong Hee Lee ),( Tapas Kuila ) 한국복합재료학회 2016 Composites research Vol.29 No.4

A self-charging supercapacitor is constructed through simple integration of the energy storage and photo exited materials at the photo electrode. The large band gap of NiO//Fe₃O₄ heterostructure generates photo electron at the photo electrode and store the charges through redox mechanism at the counter electrode. Sulfanilic acid azocromotrop/reduced graphene oxide layer at the photo electrode trapped the photo generated hole and store the charge by forming double layer. The solar supercapacitor device is charged within 400 s up to 0.5 V and exhibited a high specific capacitance of ~908 F/g against 1.5 A/g load. The solar illuminated supercapacitor shows a high energy and power density of 33.4 Wh/kg and 385 W/kg along with a very low relaxation time of ~15 ms ensuring the utility of the self charging device in the various field of energy storage and optoelectronic application.

Growth of Ni–Co binary hydroxide on a reduced graphene oxide surface by a successive ionic layer adsorption and reaction (SILAR) method for high performance asymmetric supercapacitor electrodes

Jana, Milan,Saha, Sanjit,Samanta, Pranab,Murmu, Naresh Chandra,Kim, Nam Hoon,Kuila, Tapas,Lee, Joong Hee The Royal Society of Chemistry 2016 Journal of Materials Chemistry A Vol.4 No.6

<▼1><P>Ni–Co–BH–G was prepared by using a SILAR technique and the corresponding asymmetric supercapacitor showed an energy density of 92 W h kg<SUP>−1</SUP>.</P></▼1><▼2><P>A simple, additive-free, cost-effective and scalable successive ionic layer adsorption and reaction (SILAR) method is reported to prepare nickel–cobalt binary hydroxide (Ni–Co–BH) on a reduced graphene oxide (RGO) directing template over a macro-porous conductive nickel foam substrate. This green technique is not only considered as fundamental research interest, but also describes the commercial applications of supercapacitors to reduce the electrode fabrication cost. Three different Ni–Co–BH–G (Ni–Co–BH/RGO) composites are synthesised by tailoring the nickel–cobalt ratios. The flower-like 3D framework of Ni–Co–BH–G provides a porous nano-structure to facilitate the charge transfer and ion diffusion. The cathodic peak current density <I>vs.</I> square root of the scan rate slope values of cyclic voltammetry are consistent with specific capacitance (SC) retention (<I>vs.</I> current density) from charge–discharge curves and the diffusion time constant of the Nyquist plot of the Ni–Co–BH–G composites. Taking the advantage of 3D conductive mesoporous open framework, the Ni–Co–BH–G has provided an excellent SC of 2130 F g<SUP>−1</SUP> at 2 A g<SUP>−1</SUP>. An asymmetric supercapacitor device is designed with the optimized Ni–Co–BH–G as the positive electrode and concentrated HNO3 treated conducting carbon cloth (CCN) as the negative electrode. An excellent energy density of ∼92 W h kg<SUP>−1</SUP> and a high power density of ∼7.0 kW kg<SUP>−1</SUP> with lifetime stability up to 10 000 charge–discharge cycles (capacitance retention ∼ 80%) are provided by the asymmetric device. Four asymmetric devices have been assembled in series, which provided ∼5.6 V charge–discharge potential. The assembled system has powered a 5 V light-emitting diode (LED) successfully.</P></▼2>

Investigation of the mechanical and thermal properties of <small>L</small>-glutathione modified graphene/epoxy composites

Chhetri, Suman,Adak, Nitai Chandra,Samanta, Pranab,Murmu, Naresh Chandra,Hui, David,Kuila, Tapas,Lee, Joong Hee Elsevier 2018 Composites Part B, Engineering Vol.143 No.-

<P><B>Abstract</B></P> <P>Nacre-like graphene nanosheets (GNS) obtained from the <SMALL>L</SMALL>-glutathione mediated reduction of graphene oxide (GO) were used to develop epoxy composites. Field emission scanning electron microscopy (FE-SEM) revealed the layer-by-layer nacre-like structure of GNS. Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, and thermogravimetric analysis (TGA) measurements confirmed the successful reduction of GO. The oxidized product of <SMALL>L</SMALL>-glutathione is expected to perform as capping agent to stabilize the GNS, and also stitches the graphene sheets through hydrogen bonding. Transmission electron microscopy was used to confirm the dispersion of GNS in the epoxy matrix. The GNS/epoxy composites showed significant improvement of ∼91% in fracture toughness (K<SUB>IC</SUB>), 46% in flexural strength, and 71% in flexural modulus at 0.25 wt% GNS loadings. The probable toughening mechanism was elucidated from fracture FE-SEM images. The improved compatibility and strong interfacial interaction were reflected in the enhanced storage modulus value. The thermal stability of the composites as investigated by TGA showed appreciable improvement in the degradation temperature.</P>

One pot synthesis of Cu₂O/RGO composite using mango bark extract and exploration of its electrochemical properties

Kumar, J. Sharath,Jana, Milan,Khanra, Partha,Samanta, Pranab,Koo, Hyeyoung,Murmu, Naresh Chandra,Kuila, Tapas Elsevier 2016 ELECTROCHIMICA ACTA Vol.193 No.-

<P><B>Abstract</B></P> <P>A facile and eco-friendly approach for the simultaneous reduction of graphene oxide (GO) as well as copper acetate to prepare Cu<SUB>2</SUB>O decorated reduced GO (RGO) has been demonstrated. Herein, an easily available and naturally occurring mango bark (<I>M. indica</I>) extract has been used as the reducing agent instead of hazardous and toxic chemicals. Fourier transform infrared and X-ray photoelectron spectroscopy have been performed to confirm the removal of oxygen functional groups from the surface of GO. X-ray diffraction pattern reveals the formation of Cu<SUB>2</SUB>O nanoparticles (NPs). Morphological characterization was carried out using field emission scanning electron and transmission electron microscopy to confirm the decoration of RGO with Cu<SUB>2</SUB>O NPs. The electrocatalytic behaviour of the RGO/Cu<SUB>2</SUB>O composite has been carried by cyclic voltammetry and amperometric analysis. It shows the utility of the RGO/Cu<SUB>2</SUB>O composite as an electrochemical sensor towards H<SUB>2</SUB>O<SUB>2</SUB> detection. The sensitivity and limit of detection for the composite are found to be 7.435μAμM<SUP>−1</SUP> & 42.35nM, respectively. The RGO/Cu<SUB>2</SUB>O//RGO asymmetric supercapacitor device shows the specific capacitance (SC) of 195Fg<SUP>−1</SUP> at a current density of 2Ag<SUP>−1</SUP> and energy density of 37.7 Whkg<SUP>−1</SUP> with 79% retention in SC after 5000 charge-discharge cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Simultaneous bio-reduction of GO and CuSO<SUB>4</SUB> using mango bark extract is presented. </LI> <LI> The sensitivity and the LoD for H<SUB>2</SUB>O<SUB>2</SUB> are found to be 7.435μAμM<SUP>−1</SUP> & 42.35nM. </LI> <LI> Specific capacitance of the asymmetric device is 195Fg<SUP>−1</SUP> at 2Ag<SUP>−1</SUP>. </LI> <LI> Retention in specific capacitances is ∼79% after 5000 charge-discharge cycles. </LI> </UL> </P>

Covalent surface modification of chemically derived graphene and its application as supercapacitor electrode material

Jana, Milan,Khanra, Partha,Murmu, Naresh Chandra,Samanta, Pranab,Lee, Joong Hee,Kuila, Tapas The Royal Society of Chemistry 2014 Physical chemistry chemical physics Vol.16 No.16

<P>A simple and effective method using 6-amino-4-hydroxy-2-naphthalenesulfonic acid (ANS) for the synthesis of water dispersible graphene has been described. Ultraviolet-visible (UV-vis) spectroscopy reveals that ANS-modified reduced graphene oxide (ANS-rGO) obeys Beers law at moderate concentrations. Fourier transform infrared and X-ray photoelectron spectroscopies provide quantitative information regarding the removal of oxygen functional groups from graphene oxide (GO) and the appearance of new functionalities in ANS-rGO. The electrochemical performances of ANS-rGO have been determined by cyclic voltammetry, charge–discharge and electrochemical impedance spectroscopy analysis. Charge–discharge experiments show that ANS-rGO is an outstanding supercapacitor electrode material due to its high specific capacitance (375 F g<SUP>−1</SUP> at a current density of 1.3 A g<SUP>−1</SUP>) and very good electrochemical cyclic stability (∼97.5% retention in specific capacitance after 1000 charge–discharge cycles). ANS-rGO exhibits promising characteristics with a very high power density (1328 W kg<SUP>−1</SUP>) and energy density (213 W h kg<SUP>−1</SUP>).</P> <P>Graphic Abstract</P><P>A simple and effective method using 6-amino-4-hydroxy-2-napthalenesulfonic acid (ANS) for the synthesis of water dispersible graphene is described. The as-produced graphene is a promising supercapacitor electrode material. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cp54510e'> </P>