@article { ISI:000238294800037, title = {Suppression of electron-transfer characteristics of ferrocene by OTS monolayer on a silicon/electrolyte interface}, journal = {Journal of Colloid and Interface Science}, volume = {299}, number = {2}, year = {2006}, month = {JUL}, pages = {777-784}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The passivating behavior of self-assembled monolayers (SAMs) of octadecyltrichlorosilane (OTS) on an n-type Si(100) electrode with and without a redox species like ferrocene in a polar non-aqueous medium has been investigated using techniques like contact angle measurements, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) to understand the role of the monolayer. The electron-transfer behavior of ferrocene is found to be drastically affected by the presence of monolayer and the reasons for these are analyzed as a function of the change in resistance, dielectric thickness and coverage of the monolayer. Electrochemical impedance analysis in the presence of ferrocene gives the monolayer coverage as 0.998 and the apparent rate constant calculated from this gives 4.85 x 10(-12) cm s(-1) in comparison with 4.4 x 10(-8) cm s(-1) for a similar electrode without any monolayer. A positive shift of 200 mV in the flat-band potential after monolayer formation also suggests the covalent coupling of the silane nionolayer offering a protective barrier. (c) 2006 Elsevier Inc. All rights reserved.

}, keywords = {cyclic voltammetry, ferrocene, impedance analysis, octadecyltrichlorosilane (OTS), rate constant, self-assembled monolayer (SAM)}, issn = {0021-9797}, doi = {10.1016/j.jcis.2006.03.013}, author = {Kulkarni, S. A. and Kakade, Bhalchandra A. and Mulla, Imtiaz S. and Pillai, V. K.} } @article { ISI:000329137400081, title = {Design of a high performance thin all-solid-state supercapacitor mimicking the active interface of its liquid-state counterpart}, journal = {ACS Applied Materials \& Interfaces}, volume = {5}, number = {24}, year = {2013}, month = {DEC}, pages = {13397-13404}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Here we report an all-solid-state supercapacitor (ASSP) which closely mimics the electrode-electrolyte interface of its liquid-state counterpart by impregnating polyaniline (PANO-coated carbon paper with polyvinyl alcohol-H2SO4 (PVA-H2SO4) gel/plasticized polymer electrolyte. The well penetrated PVA-H2SO4 network along the porous carbon matrix essentially enhanced the electrode-electrolyte interface of the resulting device with a very low equivalent series resistance (ESR) of 1 Omega/cm(2) and established an interfacial structure very similar to a liquid electrolyte. The designed interface of the device was confirmed by cross-sectional elemental mapping and scanning electron microscopy (SEM) images. The PANI in the device displayed a specific capacitance of 647 F/g with an areal capacitance of 1 F/cm(2) at 0.5 A/g and a capacitance retention of 62\% at 20 A/g. The above values are the highest among those reported for any solid-state-supercapacitor. The whole device, including the electrolyte, shows a capacitance of 12 F/g with a significantly low leakage current of 16 mu A(2). Apart from this, the device showed excellent stability for 10000 cycles with a coulombic efficiency of 100\%. Energy density of the PANI in the device is 14.3 Wh/kg.

}, keywords = {all-solid-state, cyclic voltametry, impedance analysis, polyaniline, polyvinyl alcohol, supercapacitor}, issn = {1944-8244}, doi = {10.1021/am404320e}, author = {Anothumakkool, Bihag and Torris, Arun A. T. and Bhange, Siddheshwar N. and Unni, SreeKuttan M. and Badiger, Manohar V. and Kurungot, Sreekumar} } @article { ISI:000368651100021, title = {High-Performance flexible solid-state supercapacitor with an extended nanoregime interface through in situ polymer electrolyte generation}, journal = {ACS Applied Materials \& Interfaces}, volume = {8}, number = {2}, year = {2016}, month = {JAN}, pages = {1233-1241}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

{Here, we report an efficient strategy by which a significantly enhanced electrodeelectrolyte interface in an electrode for supercapacitor application could be accomplished by allowing in situ polymer gel electrolyte generation inside the nanopores of the electrodes. This unique and highly efficient strategy could be conceived by judiciously maintaining ultraviolet-triggered polymerization of a monomer mixture in the presence of a high-surface-area porous carbon. The method is very simple and scalable, and a prototype, flexible solid-state supercapacitor could even be demonstrated in an encapsulation-free condition by using the commercial-grade electrodes (thickness = 150 mu m

}, keywords = {cyclic voltametry, impedance analysis, in situ polymer generation, interface, polymer electrolyte, supercapacitor}, issn = {1944-8244}, doi = {10.1021/acsami.5b09677}, author = {Anothumakkool, Bihag and Torris, Arun A. T. and Veeliyath, Sajna and Vijayakumar, Vidyanand and Badiger, Manohar V. and Kurungot, Sreekumar} } @article { ISI:000368563000067, title = {Pt- and TCO-free flexible cathode for DSSC from highly conducting and flexible PEDOT paper prepared via in situ interfacial polymerization}, journal = {ACS Applied Materials \& Interfaces}, volume = {8}, number = {1}, year = {2016}, month = {JAN}, pages = {553-562}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Here, we report the preparation of a flexible, free-standing, Pt- and TCO-free counter electrode in dye-sensitized solar cell (DSSC)-derived from polyethylenedioxythiophene (PEDOT)-impregnated cellulose paper. The synthetic strategy of making the thin flexible PEDOT paper is simple and scalable, which can be achieved via in situ polymerization all through a roll coating technique. The very low sheet resistance (4 Omega/square) obtained from a film of 40 mu m thick PEDOT paper (PEDOT-p-5) is found to be superior to the conventional fluorine-doped tin oxide (FTO) substrate. The high conductivity (357 S/cm) displayed by PEDOT-p-5 is observed to be stable under ambient conditions as well as flexible and bending conditions. With all of these features in place, we could develop an efficient Pt- and TCO-free flexible counter electrode from PEDOT-p-5 for DSSC applications. The catalytic activity toward the tri-iodide reduction of the flexible electrode is analyzed by adopting various electrochemical methodologies. PEDOT-p-5 is found to display higher exchange current density (7.12 mA/cm(2)) and low charge transfer resistance (4.6 Omega) compared to the benchmark Pt-coated FTO glass (2.40 mA/cm(2) and 9.4 Omega, respectively). Further, a DSSC fabricated using PEDOT-p-5 as the counter electrode displays a comparable efficiency of 6.1\% relative to 6.9\% delivered by a system based on Pt/FTO as the counter electrode.

}, keywords = {counter electrode, dye-sensitized solar cell, flexible and thin devices, impedance analysis, interfacial polymerization, polyethylenedioxythiophene}, issn = {1944-8244}, doi = {10.1021/acsami.5b09579}, author = {Anothumakkool, Bihag and Agrawal, Ishita and Bhange, Siddheshwar N. and Soni, Roby and Game, Onkar S. and Ogale, Satishchandra B. and Kurungot, Sreekumar} }