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.

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>

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>

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>

Antibacterial and In vivo Cytotoxic Activities of the Leaves of Leucas aspera

Mohammad Sayed Alam,Sanjit Saha,이동웅 한국응용생명화학회 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.5

Antimicrobial and cytotoxic activities of the leaves ofLeucas aspera, a medicinal plant found in Bangladesh, wereevaluated. In vitro bactericidal activity was screened against tenpathogenic or food poisoning bacteria using the disc diffusionmethod. In vivo cytotoxicity was examined against Artemia salina(brine shrimp nauplii). The dichloromethane fraction of the methanolextract of the leaves of Leucas aspera had strong antibacterial andcytotoxic effects, whereas the ethyl acetate fraction exhibitedsignificant bactericidal activity against only Gram-positive bacterialstrains. The active constituents, α-amyrin and α-tocopherol, wereisolated for the first time from the dichloromethane fraction andtheir cytotoxic effects against A. salina were significant with LC50values of 241 and 195 ppm, respectively.

Antibacterial and In vivo Cytotoxic Activities of the Leaves of Leucas aspera

Alam, Mohammad Sayed,Saha, Sanjit,Lee, Dong-Ung 한국응용생명화학회 2014 Applied Biological Chemistry (Appl Biol Chem) Vol.57 No.5

Antimicrobial and cytotoxic activities of the leaves of Leucas aspera, a medicinal plant found in Bangladesh, were evaluated. In vitro bactericidal activity was screened against ten pathogenic or food poisoning bacteria using the disc diffusion method. In vivo cytotoxicity was examined against Artemia salina (brine shrimp nauplii). The dichloromethane fraction of the methanol extract of the leaves of Leucas aspera had strong antibacterial and cytotoxic effects, whereas the ethyl acetate fraction exhibited significant bactericidal activity against only Gram-positive bacterial strains. The active constituents, ${\alpha}$-amyrin and ${\alpha}$-tocopherol, were isolated for the first time from the dichloromethane fraction and their cytotoxic effects against A. salina were significant with $LC_{50}$ values of 241 and 195 ppm, respectively.