http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Punnoose, Dinah,Rao, S. Srinivasa,Kim, Hee-Je Elsevier 2018 Materials research bulletin Vol.102 No.-
<P><B>Abstract</B></P> <P>Cu-doped NiS with PEDOT:PSS chrysanthemum flower-like structures, which were composed of many nanopetal bunches in a radial fashion, were synthesized using a modest, eco-friendly and cost effective method. The 5 wt.% Cuph/PEDOT:PSS produced a minute amount of PEDOT:PSS, which exhibiting outstanding electrochemical performance in QDSSCs. The synergetic effects of the composite were investigated and a PCE of 4.87%, fill factor of 0.51, J<SUB>sc</SUB> of 13.75 mA cm<SUP>−2</SUP>, and V<SUB>oc</SUB> of 0.549 V in a polysulfide electrolyte were obtained. The electrode exhibited great electrocatalytic activities and lower charge transfer resistance than that of the bare NiS and Cu-doped NiS, making it a promising material for both fuel cells and QDSSCs. The improved performance of the 5 wt.% Cuph/PEDOT:PSS electrode was attributed mainly to the large surface area, greater electrical conductivity and high electrocatalytic activity.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Metal-doped NiS/PEDOT:PSS chrysanthemum flower like structure was fabricated. </LI> <LI> Deposition of PEDOT: PSS into Cu-NiS enhances the V<SUB>oc</SUB> and PCE. </LI> <LI> Introduction of PEDOT: PSS acts as a passivation layer for reducing charge recombination. </LI> <LI> Cu-NiS/PEDOT:PSS shows higher onset potential with higher limiting current density. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Punnoose, Dinah,Pavan Kumar, CH. S. S.,Seo, Hyun Woong,Shiratani, Masaharu,Reddy, Araveeti Eswar,Srinivasa Rao, S.,Thulasi-Varma, Chebrolu Venkata,Kim, Soo-Kyoung,Chung, Sang-Hwa,Kim, Hee-Je The Royal Society of Chemistry 2016 New journal of chemistry Vol.40 No.4
<P>Fast electron transport and slow interfacial electron recombination are indispensable features for efficient photo-electrodes of quantum dot sensitized solar cells (QDSSCs). This study reports the methodology to prevent recombination losses in lead sulfide QDSSCs. TiO2 nano-particles were coated with two different insulating oxide materials (MgO and Al2O3). Single-and-double coated barrier layers are used in order to optimize the passivation effect, prevent recombination losses and to obtain high-performance stable QDSSCs when compared to bare TiO2. Metal oxides with a high isoelectric point enhance quantum dot adsorption and also increase the TiO2 conduction band edge. QDSSCs are examined in detail using a polysulfide electrolyte and a copper sulfide (CuS) counter electrode. A solar cell based on a double coating electrode (MgO/Al2O3) yielded excellent performance with an efficiency (eta) of 3.25%. The increase in electron transport and the decrease in electron recombination are responsible for the enhanced J(SC) and V-OC of QDSSCs. The electron lifetime with TiO2/MgO/Al2O3 was higher than those with bare TiO2, TiO2/MgO, TiO2/Al2O3 and TiO2/Al2O3/MgO leading to a more efficient electron-hole separation and slows down electron recombination.</P>
Punnoose, D.,Suh, S.M.,Kim, B.J.,kim, S.k.,Kumar, Ch.S.S.P.,Rao, S.S.,Thulasi-Varma, C.V.,Reddy, A.E.,Chung, S.H.,Kim, H.J. Elsevier Sequoia 2016 Journal of Electroanalytical Chemistry Vol.773 No.-
<P>The deposition techniques of quantum dots (QDs) have great influence on the photovoltaic performances of quantum dot sensitised solar cells (QDSSCs). In this study, we report CdS/CdSe sensitised TiO2 solar cells focussing on the influence of two commonly used in situ QD deposition techniques (SILAR: successive ionic layer adsorption and reaction and CBD: chemical bath deposition). In addition to this, the QDSSC performance is enhanced due to better light harvesting capability of PbS quantum dots and makes large accumulation of photo-injected electrons in the conduction band of TiO2. When compared to power conversion efficiency (PCE) of 4.58% was obtained for PbS/CBD-CdS/CBD-CdSe cells when compared to PbS/SILAR-CdS/SILAR-CdSe. With chemical bath deposition, we achieved high surface coverage of QDs, which contributes to the increase in photocurrent,open circuit voltage and fill factor. Impedance spectroscopy revealed that the PbS/CBD-CdS/CBD-CdSe reduces recombination and increases charge collection efficiency and a long electron lifetime was achieved. To associate the assembling of QDs with the performance of QDSSCs a methodical characterization of morphology, optical and electro-chemical properties and its stability has been studied. We achieved PbS seeded CBD highlighting its robust consequences for the performance of QDSSCs. (C) 2016 Elsevier B.V. All rights reserved.</P>
Layer by layer approach to enhance capacitance using metal sulfides for supercapacitor applications
Subramanian, Archana,Punnoose, Dinah,Raman, Vivekanandan,Gopi, Chandu V.V. Muralee,Rao, Sunkara Srinivasa,Khan, Muhammad Adil,Kim, Hee-Je Elsevier 2018 Materials letters Vol.231 No.-
<P><B>Abstract</B></P> <P>Layer-by-layer approach for NiS, CoS and PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) is being fabricated. Metal sulfides have always been chosen for their remarkable electrochemical characteristics and wide beneficial domains, such as electrochemical energy conversion and storage. This work presents the preparation of cost-effective metal sulfides (NiS, NiS/CoS, NiS/CoS/PEDOT:PSS) developed on nickel foam sheets for supercapacitor (SC) applications. The assembled NiS/CoS/PEDOT:PSS array SC device exhibits an utmost energy density of 30.3 W h kg<SUP>−1</SUP> and specific capacitance of 353 F g<SUP>−1</SUP>. All wet processing methods of fabrication accompanied with superior performance characteristics make these SCs very attractive for the next generation flexible energy storage systems.</P> <P><B>Highlights</B></P> <P> <UL> <LI> NiS/CoS/PEDOT:PSS on nickel foam is coated by Chemical Bath Deposition method. </LI> <LI> Metal sulfides extend active area due to low electronegativity of sulfur over oxygen. </LI> <LI> PEDOT:PSS on NiS/CoS is coated to increase surface area and conductivity. </LI> <LI> NiS/CoS/PEDOT:PSS showed maximal specific capacitance of 353 F g<SUP>−1</SUP> at 15 mA cm<SUP>−2</SUP>. </LI> </UL> </P>
Naresh, Bandari,Punnoose, Dinah,Rao, S. Srinivasa,Subramanian, Archana,Raja Ramesh, B.,Kim, Hee-Je The Royal Society of Chemistry 2018 NEW JOURNAL OF CHEMISTRY Vol.42 No.4
<P>Metal sulfides have attracted considerable scrutiny compared to metal oxides owing to their distinguished electrochemical properties and various applications, such as solar cells and supercapacitors. We have reported the pseudocapacitive properties of morphology-tuned NiS nanostructures using a hydrothermal method at different deposition times and temperatures. The surface morphology, structure, and chemical composition have been confirmed by SEM, TEM, XRD, XPS and EDS analyses. The optimized NiS-2 h electrode offers extra conductive paths on nickel foam, yielding a lower charge-transfer resistance and internal resistance than those of NiS-1 h and NiS-3 h. An investigation of its electrochemical properties indicates that the NiS electrode exhibited a specific capacitance of 1073.8 F g<SUP>−1</SUP> and 959 F g<SUP>−1</SUP> at current densities of 1.2 and 2.4 A g<SUP>−1</SUP> in KOH solution, indicating its potential to be used in practical applications. Moreover, it delivered a maximum energy density of 23.19 W h kg<SUP>−1</SUP> and a power density of 243.9 W kg<SUP>−1</SUP> with an excellent cycling retention of 89% after 1000 charge-discharge cycles. This work also indicates an effective approach for the fabrication of high-performance electrodes in a cost-effective manner for higher energy density and power density applications, such as electric vehicles, flexible electronics, and energy storage devices.</P>
S., Srinivasa Rao,Punnoose, Dinah,Bae, Jin-Ho,Durga, Ikkurthi Kanaka,Thulasi-Varma, Chebrolu Venkata,Naresh, Bandari,Subramanian, Archana,Raman, Vivekanandan,Kim, Hee-Je Elsevier 2017 ELECTROCHIMICA ACTA Vol.254 No.-
<P><B>Abstract</B></P> <P>This paper reports the facile synthesis of a novel architectural of NiS/PEDOT:PSS with DEG, where the complementary features of the three components (well-defined NiS black pepper like nanoparticles on nickel foam, an ultrathin layers of poly (3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS), and diethylene glycol (DEG)) are deposited sequentially to a single entity to fabricate a high-performance electrode for supercapacitor applications. Owing to the high electrical conductivity of the well-defined NiS nanoparticles, in which the conductivity, and good chemical and electrochemical stability is enhanced further by the PEDOT:PSS and DEG thin layers, the as-fabricated NiS/PEDOT:PSS with a DEG chrysanthemum petal-like nanostructure exhibits good rate capability, excellent cycling stability, and high specific capacitance. The PEDOT:PSS with DEG offers extra conductive paths for each layer on NiS, yielding a lower internal resistance and charge-transfer resistance than that of the NiS/PEDOT:PSS without DEG. As a result, the NiS/PEDOT:PSS with the DEG electrode shows a tremendous pseudocapacitance of 750.64Fg<SUP>−1</SUP> at 1.11Ag<SUP>−1</SUP>, along with a high energy density of 24.52Whkg<SUP>−1</SUP> at a power density of 138.88Wkg<SUP>−1</SUP> and good cycling stability, suggesting that it is a promising candidate for energy storage. The unique performance of NiS/PEDOT:PSS with a DEG benefits from its unique chrysanthemum petal-like nanostructure, which could offer faster ion and electron transfer ability, greater reaction surface area and good structural stability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> NiS/PEDOT:PSS with DEG chrysanthemum petals were prepared using a facile bar-coating method. </LI> <LI> NiS/PEDOT:PSS with DEG showed greater electrochemical properties. </LI> <LI> Improved penetration of electrolyte ions into the electrode was observed by the attachment PEDOT:PSS on NiS. </LI> <LI> The electrode exhibited a high specific capacitance of 750.64Fg<SUP>−1</SUP> at 1.11Ag<SUP>−1</SUP>. </LI> <LI> The nanocomposite displayed excellent cycling stability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Durga, I.,Rao, S. S.,Punnoose, D.,Kundakarla, N.,Tulasivarma, C.,Kim, H. J. Royal Society of Chemistry 2017 New journal of chemistry Vol.41 No.5
<P>A novel approach for the synthesis of CoxNiyS nanoparticles on fluorine-doped tin oxide (FTO) and nickel-foam (Ni-foam) substrates for methanol oxidation in alkaline media is described. The introduced electrocatalyst was synthesized using different concentrations of cobalt (Co) and nickel (Ni) via a simple and effective process; the electrochemical properties were assessed by cyclic voltammetry. The Co90%Ni10% catalyst showed a current density of -0.576 and -0.801 mA on FTO and Ni-foam, respectively, which is the best for the oxygen reduction reaction. The observed electrocatalytic activity proves that the Ni content plays a crucial role in the enhanced current density. Co90%Ni10% also showed superior stability; 78.75% of the electroactive area remained compared to 67.31% in the case of Co0%Ni100% on Ni-foam. Moreover, the optimized catalyst was used as a counter electrode (CE) in quantum-dot sensitized solar cells and showed greater catalytic activity in a polysulfide redox electrolyte than CuS and Pt based CEs. As a result, under 1 sun illumination, Co90%Ni10% exhibited a power conversion efficiency of up to 2.89%, which was much higher than that of the Pt (1.32%) and CuS (2.03%) CEs. The power conversion efficiency of Co90%Ni10% was enhanced by the surface morphology, roughness factor, and current density, which permit prompt electron transport and lower the charge transfer resistance rate for the polysulfide redox electrolyte.</P>