Sponge-like β-Ni(OH)2 nanoparticles: synthesis, characterization and electrochemical properties

Dubal, D. P.,Lee, S. H.,Kim, W. B. Springer-Verlag 2012 JOURNAL OF MATERIALS SCIENCE - Vol.47 No.8

Porous polypyrrole clusters prepared by electropolymerization for a high performance supercapacitor

Dubal, Deepak P.,Lee, Sang Ho,Kim, Jong Guk,Kim, Won Bae,Lokhande, Chandrakant D. The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.7

<P>Different nanostructures (Ns), such as nanobelts, nanobricks and nanosheets, of polypyrrole (PPy) were successfully fabricated on stainless steel substrates by simply varying the scan rate of deposition in the potentiodynamic mode. These PPy Ns were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and surface area measurement. The XRD analysis showed the formation of amorphous PPy thin films, and the FTIR studies confirmed characteristic chemical bonding in the PPy materials. SEM images depicted that a high scan rate of deposition can form multilayer nanosheets with high porosity leading to a system with excellent processability. The PPy nanosheets possess a higher Brunauer–Emmett–Teller (BET) surface area of 37.1 m<SUP>2</SUP> g<SUP>−1</SUP> than PPy nanobelts and nanobricks. The supercapacitive performances of different PPy Ns were evaluated using cyclic voltammetry (CV) and galvanostatic charge–discharge techniques in 0.5 M H<SUB>2</SUB>SO<SUB>4</SUB>. A maximum specific capacitance of 586 F g<SUP>−1</SUP> was obtained for multilayer nanosheets at a scan rate of 2 mV s<SUP>−1</SUP>. In addition, impedance measurements of the different Ns of PPy electrodes were performed suggesting that the PPy electrodes with multilayer nanosheets are promising materials for the next generation high performance electrochemical supercapacitors.</P> <P>Graphic Abstract</P><P>Simple and inexpensive electropolymerization enables the synthesis of three dimensional PPy nanostructures with large area and flexibility for applications in supercapacitors. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm14470k'> </P>

Hydrophilic polyaniline nanofibrous architecture using electrosynthesis method for supercapacitor application

D.S. Dhawale,R.R. Salunkhe,V.S. Jamadade,D.P. Dubal,S.M. Pawar,C.D. Lokhande 한국물리학회 2010 Current Applied Physics Vol.10 No.3

An electrosynthesis process of hydrophilic polyaniline nanofiber electrode for electrochemical supercapacitor is described. The TGA–DTA study showed polyaniline thermally stable up to 323 K. Polyaniline nanofibers exhibit amorphous nature as confirmed from XRD study. Smooth interconnected fibers having diameter between 120–125 nm and length typically ranges between 400–500 nm observed from SEM and TEM analysis. Contact angle measurement indicated hydrophilic nature of polyaniline fibers. Optical study revealed the presence of direct band gap with energy 2.52 eV. The Hall effect measurement showed room temperature resistivity ~3 × 10-4 Ω cm and Hall mobility 549.35 cm-2V-1 s-1. The supercapacitive performance of nanofibrous polyaniline film tested in 1 M H2SO4 electrolyte and showed highest specific capacitance of 861 F g-1 at the voltage scan rate of 10 mV/s.

Surfactant-assisted morphological tuning of hierarchical CuO thin films for electrochemical supercapacitors

Dubal, Deepak P.,Gund, Girish S.,Holze, Rudolf,Jadhav, Harsharaj S.,Lokhande, Chandrakant D.,Park, Chan-Jin The Royal Society of Chemistry 2013 Dalton Transactions Vol.42 No.18

<P>Copper oxide (CuO) thin films are successfully synthesized using a surfactant assisted chemical bath deposition method for application in supercapacitors. The effect of organic surfactants such as Triton X-100 and polyvinyl alcohol (PVA) on structural, morphological, surface areas and electrochemical properties of CuO thin films is investigated. The films deposited using organic surfactants exhibit different surface morphologies. It is observed that the organic surfactants play important roles in modifying the morphology, surface area and pore size distribution. Electrochemical analysis confirms that the nanostructures of the electrode material play a vital role in supercapacitors. The cyclic voltammetry studies show a considerably improved high rate pseudocapacitance of CuO samples synthesized using organic surfactants. The maximum specific capacitance of 411 F g<SUP>−1</SUP> at 5 mV s<SUP>−1</SUP> is obtained for the CuO sample prepared using an organic surfactant (Triton X-100). Furthermore, all the CuO nanostructures exhibit high power performance, excellent rate as well as long term cycling stability. The Ragone plot ascertains better power and energy densities of CuO nanostructured samples. This is an easy and simple way to tune the morphology using surfactants which can be applied for other energy storage materials.</P> <P>Graphic Abstract</P><P>Copper oxide (CuO) thin films are successfully synthesized using a surfactant assisted chemical bath deposition method for application in supercapacitors. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3dt50275a'> </P>

Metal oxide thin film based supercapacitors

C.D. Lokhande,D.P. Dubal,주오심 한국물리학회 2011 Current Applied Physics Vol.11 No.3

Supercapacitors have been known for over fifty years and are considered as one of the potential energy storage systems. Research into supercapacitors is presently based primarily on their mode of energy storage, namely: (i) the redox electrochemical capacitors and (ii) the electrochemical double layer capacitor. The commonly investigated classes of materials are transition metal oxides (notably, ruthenium oxide) and conducting polymers. Recently, many chemically deposited metal oxide thin film electrodes including ruthenium oxide, iridium oxide, manganese oxide, cobalt oxide, nickel oxide, tin oxide, iron oxide, pervoskites, ferrites etc. have been tested in supercapacitors This review presents supercapacitor performance data of metal oxide thin film electrodes. The supercapacitors exhibited the specific capacitance (Sc) values between 50 and 1100 F g^-1, which are quite comparable with bulk electrode values; therefore, it is likely that metal oxide films will continue to play a major role in supercapacitor technology.

Sb₂S₃ nanoparticles through solution chemistry on mesoporous TiO₂ for solar cell application

Salunkhe, D.B.,Gargote, S.S.,Dubal, D.P.,Kim, W.B.,Sankapal, B.R. North Holland ; Elsevier Science Ltd 2012 Chemical physics letters Vol.554 No.-

A facile room temperature (27<SUP>o</SUP>C) chemical route, namely successive ionic layer adsorption and reaction (SILAR) method is used to deposit antimony trisulphide (Sb<SUB>2</SUB>S<SUB>3</SUB>) nanoparticles on mesoporous titanium dioxide (TiO<SUB>2</SUB>). The method facilitates linker free approach to deposit the size tuned nanoparticles. The synthesized TiO<SUB>2</SUB>/Sb<SUB>2</SUB>S<SUB>3</SUB> structure on a FTO (fluorine doped tin oxide coated glass substrate) was used as a photoanode with polysulphide as liquid electrolyte and platinum coated FTO as back contact to construct the photovoltaic device. The photovoltaic performances have been tested under light illumination with standard solar simulator condition (AM 1.5G, 10mW/cm<SUP>2</SUP>) and photovoltaic parameters are discussed.

Baking impact of Fe composition on CdSe films for solar cell application

Shinde, S.K.,Dubal, D.P.,Ghodake, G.S.,Lee, D.S.,Lohar, G.M.,Rath, M.C.,Fulari, V.J. North-Holland 2014 Materials letters Vol.132 No.-

Cd<SUB>1-X</SUB>Fe<SUB>X</SUB>Se thin films were electrodeposited onto fluorine doped tin oxide coated conducting glass (FTO) and stainless steel (SS) substrates at various bath compositions with X=0.1 to 0.5 in an aqueous electrolytic bath containing CdSO<SUB>4</SUB>, FeSO<SUB>4</SUB> and SeO<SUB>2</SUB>. The effects of different compositions on physico-chemical properties of Cd1-XFeXSe thin films have been systematically investigated. The X-ray diffraction (XRD) analysis reveals the polycrystalline in nature of Cd<SUB>1-X</SUB>Fe<SUB>X</SUB>S thin films. Field emission scanning electron microscopy (FE-SEM) micrographs shows the variation in the nanostructure with varying compositions. The Cd<SUB>1-X</SUB>Fe<SUB>X</SUB>Se thin films exhibited the water contact angles in hydrophilic range. Optical absorption measurements are used to estimate the band gap value of Cd<SUB>1-X</SUB>Fe<SUB>X</SUB>Se thin films deposited at various bath compositions. The dramatic changes in surface morphology, as a consequence of different composition of Fe in CdSe matrix, significantly alter the conversion efficiency of Cd<SUB>1-X</SUB>Fe<SUB>X</SUB>Se films.

Enhanced photoelectrochemical properties of nanoflower-like hexagonal CdSe0.6Te0.4: Effect of electron beam irradiation

수렌드라,가야난고다크,Deepak P. Dubal,Haridas D. Dhaygude,김대영,Vijay J. Fulari 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

Present investigation deals with the effect of electron beam irradiation on the photoelectrochemicalproperties of cadmium selenium telluride (CdSe0.6Te0.4) thin films. Initially, CdSe0.6Te0.4 thin films wereelectrodeposited on fluorine doped tin oxide (FTO) coated glass and stainless steel substrates. Later,these CdSe0.6Te0.4 thin films were irradiated with high energy electron beam(10 MeV) of different dosesfrom 10 to 30 kilograys (kGy). The effect of electron beam irradiation on different physico-chemicalproperties of CdSe0.6Te0.4 thin films such asmorphological, structural, optical and photoelectrochemicalhas been investigated. It is observed that, the electron beam irradiation treatment considerably affectsthe properties of CdSe0.6Te0.4 thin films. The surface morphology of CdSe0.6Te0.4 thin films was changedfrom cauliflowers to nanoflowers, nanoroses and interconnected nanoflakes with doses of electronbeams. Furthermore, the effect of electron beam irradiation on photoelectrochemical properties ofCdSe0.6Te0.4 films was investigated. It is interesting to note that, the photoelectrochemical (PEC)properties of CdSe0.6Te0.4 thin films are extensively affected by electron beam irradiation. Thephotoconversion efficiency values of CdSe0.6Te0.4 films for different doses of electron beam are found tobe 0.9%, 1.1%, 2.0% and 1.5%, respectively.