02192nas a2200229 4500008004100000022001400041245008500055210006900140260000800209300001400217490000600231520147000237653001101707653001901718653001401737653001901751653002001770100001501790700002501805700002401830856010801854 2016 eng d a2196-021600a1D alignment of PEDOT in a buckypaper for high-performance solid supercapacitors0 a1D alignment of PEDOT in a buckypaper for highperformance solid  cSEP a1329-13360 v33 a

A flexible solid-state supercapacitor is prepared from carbon nanotube (CNT)-based buckypaper after forming a thin layer of polyethylenedioxythiophene (PEDOT) on the surface of the CNTs in the paper. A highly conducting PEDOT phase is obtained by interfacial polymerization, in which polymerization is confined at the interface of two immiscible liquids. The hydrophilic interaction between the functionalized CNTs and the oxidizing agent (iron perchlorate, Fe(ClO4)(3)), which is located in the aqueous phase, and the restricted interaction of the oxidizing agent with the EDOT monomer in the organic layer at the immiscible interface play a vital role in establishing a uniform and aggregate-free growth pattern of PEDOT on CNT. By carefully optimizing the amount of polymer in the paper, an electrode with a sheet resistance of 3.4(-1) and equivalent series resistance of 0.95 can be prepared. A thin and flexible solid-state supercapacitor device with an overall thickness of 210m is made by using this paper as the electrodes and poly(vinyl alcohol)/lithium chloride as the gel electrolyte. The power density and energy density of the electrode are 9.94Wcm(-3) and 8.85mWhcm(-3), respectively. The device also delivers a high volumetric capacitance of 18Fcm(-3) and areal capacitance of 354mFcm(-2). The demonstrated strategy is scalable and hence the process can be conveniently applied to prepare large-area PEDOT-modified buckypapers in a short time.

10aCarbon10aEnergy storage10ananotubes10apolymerization10aSupercapacitors1 aSoni, Roby1 aAnothumakkool, Bihag1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/1d-alignment-pedot-buckypaper-high-performance-solid-supercapacitors02544nas a2200289 4500008004100000022001400041245014300055210006900198260007100267300001200338490000600350520143900356653002201795653003001817653003001847653002301877653003101900653003101931100002501962700002001987700002802007700001502035700002002050700002902070700002402099856013102123 2016 eng d a1944-824400aPt- and TCO-free flexible cathode for DSSC from highly conducting and flexible PEDOT paper prepared via in situ interfacial polymerization0 aPt and TCOfree flexible cathode for DSSC from highly conducting  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN a553-5620 v83 a

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.

10acounter electrode10adye-sensitized solar cell10aflexible and thin devices10aimpedance analysis10ainterfacial polymerization10apolyethylenedioxythiophene1 aAnothumakkool, Bihag1 aAgrawal, Ishita1 aBhange, Siddheshwar, N.1 aSoni, Roby1 aGame, Onkar, S.1 aOgale, Satishchandra, B.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-and-tco-free-flexible-cathode-dssc-highly-conducting-and-flexible-pedot-paper-prepared-002224nas a2200157 4500008004100000245009100041210006900132260000800201490000700209520163100216100002801847700001501875700002801890700002601918856012201944 2017 eng d00aCalixarene based nanocomposite materials for high performance supercapacitor electrode0 aCalixarene based nanocomposite materials for high performance su cJUL0 v413 aA functionalised calixarene {4-Sulphatocalix [6] arene Hydrate (SC6)} stabilises MoS2/partially reduced graphene oxide (rGO) nanosheet. Such stabilised SC6-rGO/SC6-MoS2 and SC6 doped polyaniline (PANI) together forms a nanocomposite hybrid material for supercapacitor electrode. It was fabricated by an in situ polymerization method. Transmission electron microscopy (TEM) results suggest that PANI nanostructures grow homogeneously onto the surfaces of SC6 functionalised MoS2. Calixarene acts as a dopant for PANI as well as a stabiliser for the 2D nanosheets of rGO/MoS2. The characterisation of composites together with basic components was done by using various techniques namely, solid-state FT-IRspectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The electrochemical performance was analysed by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectrometry (EIS). It was found that the SC6 functionalised MoS2 and SC6 doped PANI formed a uniform nanocomposite. The synthesised composites show high specific capacitance (691 F/g) and good cycling stability during the charge-discharge process when used as supercapacitor electrodes. The improvement in electrochemical performance of composites is assigned to synergistic effect of SC6 stabilised MoS2 and doped PANI. Our investigation highlighted the importance of use of calixarene in composites for above stated supercapacitor performance. The role of calixarene in the present study opens a way for the application of alike materials in the composite supercapacitors for energy storage applications.1 aWaghmode, Babasaheb, J.1 aSoni, Roby1 aPatil, Kashinath, Rangu1 aMalkhede, Dipalee, D. uhttps://library.ncl.res.in/content/calixarene-based-nanocomposite-materials-high-performance-supercapacitor-electrode02901nas a2200301 4500008004100000022001400041245013800055210006900193260000800262300001400270490000600284520183300290653003802123653002502161653002402186653003002210653002802240653001902268100002302287700002402310700002102334700002802355700001502383700002302398700002202421700002502443856013102468 2017 eng d a2155-543500aEfficient and durable oxygen reduction electrocatalyst based on CoMn alloy oxide nanoparticles supported over N-doped porous graphene0 aEfficient and durable oxygen reduction electrocatalyst based on  cOCT a6700-67100 v73 aTransition metal oxide derived materials are very important for various applications, such as electronics, magnetism, catalysis, electrochemical energy conversion, and storage. Development of efficient and durable catalysts for the oxygen reduction reaction (ORR), an important reaction in fuel cells and metal air batteries, is highly desirable. Moreover, the futuristic catalysts for these applications need to be costeffective in order to ensure a competitive edge for these devices in the energy market. This article describes the synthesis of a cost-effective and efficient electrocatalyst for ORR It is based on supporting CoMn alloy oxide nano particles on N-doped porous graphene through a simple and scalable microwave irradiation method. Microwave irradiation was found to be very crucial for the fast creation of pores in the graphene framework with a concomitant formation of the CoMn alloy oxide nanoparticles. A series of catalysts have been synthesized by varying the Co:Mn ratio, among which, the one with the Co:Mn ratio of 2:1 [designated as CoMn/pNGr(2:1)] displayed remarkably higher ORR activity in 0.1 M KOH solution. It showed a similar to 60 mV potential shift with a low Tafel slope of 74 mV/decade, which is comparable to that derived from the commercial Pt/C catalyst. This high activity of CoMn/pNGr(2:1) has been credited to the cooperative effect arising from the metal entities and the defects present in the N-doped porous graphene. Finally, real system-level validations of the use of CoMn/pNGr(2:1) as cathode catalyst could be performed by fabricating and testing single-cells of an anion-exchange membrane fuel cell (AEMFC) and a primary Zn-air battery, which successfully demonstrated the efficiency of the catalyst to facilitate ORR in real integrated systems of the single-cell assemblies.10aanion-exchange membrane fuel cell10acooperativity effect10amicrowave synthesis10aoxygen reduction reaction10aporous N-doped graphene10aZn-air battery1 aSingh, Santosh, K.1 aKashyap, Varchaswal1 aManna, Narugopal1 aBhange, Siddheshwar, N.1 aSoni, Roby1 aBoukherroub, Rabah1 aSzunerits, Sabine1 aKurungot, Sreekurnar uhttps://library.ncl.res.in/content/efficient-and-durable-oxygen-reduction-electrocatalyst-based-comn-alloy-oxide-nanoparticles01669nas a2200169 4500008004100000022001400041245011900055210006900174260000900243300001400252490000600266520104300272100001501315700002101330700002401351856012401375 2017 eng d a2040-336400aGrafoil-scotch tape-derived highly conducting flexible substrate and its application as a supercapacitor electrode0 aGrafoilscotch tapederived highly conducting flexible substrate a cMAR  a3593-36000 v93 a

Development of flexible supercapacitors is limited by the availability of flexible and durable conducting substrates; a conducting and cheap substrate for the active material deposition is essential for breakthrough progress in this direction. In this report, a highly flexible, conducting, and cheap substrate is prepared by simple stick and peel-off method involving Scotch tape and Grafoil. A Grafoil-Scotch tape derived flexible substrate exhibits a sheet resistance of 7 Omega square(-1) along with a high degree of flexibility and durability. Moreover, its properties are further enhanced by the anodization in order to increase the hydrophilicity and surface area. The substrate is highly thin with a thickness of just 74 mu m. Its practical utility has been demonstrated by electrodepositing MnO2 as an active material and, thereafter, fabricating a solid-state flexible supercapacitor. The fabricated device exhibits high capacitance retention under bent (99%) and twisted (98%) conditions along with a low ESR of 7 Omega.

1 aSoni, Roby1 aRaveendran, Alka1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/grafoil-scotch-tape-derived-highly-conducting-flexible-substrate-and-its-application02108nas a2200181 4500008004100000022001400041245012400055210006900179260000800248300001200256490000700268520145700275100002001732700001501752700002401767700001701791856011801808 2018 eng d a0024-929700aNaphthalene diimide copolymers by direct arylation polycondensation as highly stable supercapacitor electrode materials0 aNaphthalene diimide copolymers by direct arylation polycondensat cFEB a954-9650 v513 a

Conjugated donor-acceptor copolymers based on naphthalene diimide (NDI) as acceptor and thiopheneterminated oligophenylenevinylene as donor moieties (P-1 and P-2, respectively) were synthesized using the direct (hetero) arylation (DHAP) polymerization route. Nitrile groups were introduced at the vinylene linkage in one copolymer (P-2) to fine-tune its electrochemical properties. Both polymers show) pi-pi* transition in the 300-480 nm region and intramolecular charge transfer (ICT) from thiophene to NDI in the 500-800 nm region in the absorption spectra. P-2 exhibits a blue-shifted intramolecular charge transfer (ICT) band in the absorption spectrum as well as a lower reduction potential in the cyclic voltammogram compared to the analogous polymer without the nitrile substitution (P-1). The two polymers were evaluated as type III supercapacitor materials by preparing composite electrodes with carbon nanotubes (CNTs) and employing 0.5 M H2SO4 as the electrolyte. Their performance was compared with that of P(NDI2OD-T2) as a reference polymer. The polymer P-2 based supercapacitor exhibits a specific capacitance of 124 F/g with excellent stability up to 5000 cycles with almost 100% retention of the initial capacitance in the potential window of -0.7 to 0.5 V. Compared to P-2, P-1 exhibits a specific capacitance of 84 F/g, while the corresponding value for the reference polymer P(NDI2OD-T2) is 61 F/g under identical conditions.

1 aSharma, Sandeep1 aSoni, Roby1 aKurungot, Sreekumar1 aAsha, S., K. uhttps://library.ncl.res.in/content/naphthalene-diimide-copolymers-direct-arylation-polycondensation-highly-stable02540nas a2200169 4500008004100000245015500041210006900196260000800265300001400273490000700287520186400294100001702158700002702175700001502202700002402217856012902241 2018 eng d00aRationally designed self-standing V2O5 electrode for high voltage non-aqueous all-solid-state symmetric (2.0 V) and asymmetric (2.8 V) supercapacitors0 aRationally designed selfstanding V2O5 electrode for high voltage cMAY a8741-87510 v103 aThe maximum capacitive potential window of certain pseudocapacitive materials cannot be accessed in aqueous electrolytes owing to the low dissociation potential of 1.2 V possessed by water molecules. However, the inferior pseudocapacitance exhibited by the commonly used electrode materials when integrated with non-aqueous electrolytes still remains a challenge in the development of supercapacitors (SC). Proper selection of materials for the electrode and a rational design process are indeed important to overcome these practical intricacies so that such systems can perform well with non-aqueous electrolytes. We address this challenge by fabricating a prototype all-solid-state device designed with high-capacitive V2O5 as the electrode material along with a Li-ion conducting organic electrolyte. V2O5 is synthesized on a pre-treated carbon-fibre paper by adopting an electrochemical deposition technique that effects an improved contact resistance. A judicious electrode preparation strategy makes it possible to overcome the constraints of the low ionic and electrical conductivities imposed by the electrolyte and electrode material, respectively. The device, assembled in a symmetrical fashion, achieves a high specific capacitance of 406 F g(-1) (at 1 A g(-1)). The profitable aspect of using an organic electrolyte is also demonstrated with an asymmetric configuration by using activated carbon as the positive and V2O5 as the negative electrode materials, respectively. The asymmetric device displays a wide working-voltage window of 2.8 V and delivers a high energy density of 102.68 W h kg(-1) at a power density of 1.49 kW kg(-1). Moreover, the low equivalent series resistance of 9.9 Omega and negligible charge transfer resistance are observed in the impedance spectra, which is a key factor that accounts for such an exemplary performance.1 aGhosh, Meena1 aVijayakumar, Vidyanand1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/rationally-designed-self-standing-v2o5-electrode-high-voltage-non-aqueous-all-solid-state02522nas a2200253 4500008004100000022001400041245015300055210006900208260000800277300001200285490000700297520158900304653004001893653003801933653002601971653001601997653001902013653002102032100001502053700002402068700002002092700002402112856013202136 2018 eng d a1944-824400aRealizing high capacitance and rate capability in polyaniline by enhancing the electrochemical surface area through induction of superhydrophilicity0 aRealizing high capacitance and rate capability in polyaniline by cJAN a676-6860 v103 a

Polyaniline (PANI) as a pseudocapacitive material has very high theoretical capacitance of 2000 F g(-1). However, its practical capacitance has been limited by low electrochemical surface area (ESA) and unfavorable wettability toward aqueous electrolytes. This work deals with a strategy wherein the high ESA of PANI has been achieved by the induction of superhydrophilicity together with the alignment of PANI exclusively on the surface of carbon fibers as a thin layer to form a hybrid assembly. Superhydrophilicity is induced by electrochemical functionalization of the Toray carbon paper, which further induces superhydrophilicity to the electrodeposited PANI layer on the paper, thereby ensuring a high electrode-electrolyte interface. The Toray paper is electrochemically functionalized by the anodization method, which generates a highly active electrochemical surface as well as greater wettability (superhydrophilic) of the carbon fibers. Because of the strong interaction of anilinium chloride with the hydrophilic carbon surface, PANI is polymerized exclusively over the surface of the fibers without any appreciable aggregation or agglomeration of the polymer. The PANI-Toray paper assembly in the solid-state prototype supercapacitor can provide a high gravimetric capacitance of 1335 F g(-1) as well as a high areal capacitance of 1.3 F cm(-2) at a current density of 10 A g(-1). The device also exhibits high rate capability, delivering 1217 F g(-1) at a current density of 50 A g(-1) and a high energy density of 30 W h kg(-1) at a power density of 2 kW kg(-1).

10aelectrochemical active sulfate area10aelectrochemical functionalization10aelectropolymerization10apolyaniline10asupercapacitor10asuperhydrophilic1 aSoni, Roby1 aKashyap, Varchaswal1 aNagaraju, Divya1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/realizing-high-capacitance-and-rate-capability-polyaniline-enhancing-electrochemical-surface02008nas a2200169 4500008004100000022001400041245016300055210006900218260000900287300001400296490000700310520132200317100001501639700002801654700002401682856013201706 2019 eng d a2040-336400a3-D nanoribbon-like Pt-free oxygen reduction reaction electrocatalyst derived from waste leather for anion exchange membrane fuel cells and zinc-air batteries0 a3D nanoribbonlike Ptfree oxygen reduction reaction electrocataly cAPR  a7893-79020 v113 a

Fe-N-x and Fe-S-based ORR electrocatalysts have emerged as rightful candidates to replace Pt in fuel cells to make the technology cheap and sustainable. Fe-N-C catalysts are generally prepared by the pyrolysis of conducting polymers, metal-organic frameworks, aerogels, etc., and the combination of multiple heteroatoms and metal precursors. These precursors are mostly expensive and their synthesis involves multiple steps. In this report, we have demonstrated the synthesis of a Fe-N-C catalyst from the waste leather obtained from the footwear and other leather-consuming industries. The pyrolysis of leather with FeCl3 (metal source) results in the formation of a highly thin and porous nano-ribbon like morphology. Waste leather acts as a cost-free single source of heteroatoms like N, S and carbon. The catalyst synthesized at a temperature of 900 degrees C shows an overpotential of 40 mV and better durability compared to the commercial Pt/C catalyst. The catalyst is demonstrated as the cathode for alkaline exchange membrane fuel cell (AEMFC) and zinc-air battery (ZAB) applications. In the AEMFC, a power density of 50 mW cm(-2) and an OCV of 0.92 V are obtained whereas, in the ZAB, it exhibited a power density of 174 mW cm(-2) compared to 160 mW cm(-2) of the system based on the Pt/C catalyst.

1 aSoni, Roby1 aBhange, Siddheshwar, N.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/3-d-nanoribbon-pt-free-oxygen-reduction-reaction-electrocatalyst-derived-waste-leather-anion01660nas a2200157 4500008004100000022001400041245009900055210006900154260000800223300001200231490000700243520108800250100001501338700002401353856012501377 2019 eng d a1144-054600aFe2P4O12-carbon composite as a highly stable electrode material for electrochemical capacitors0 aFe2P4O12carbon composite as a highly stable electrode material f cJAN a399-4060 v433 a

Supercapacitors are important energy storage devices for high power applications. Carbon materials, metal oxides and conducting polymers have been known to show capacitive charge storage but transition metal phosphates are not as well-known as electrode materials in supercapacitors. In this study, an iron cyclotetraphosphate (Fe2P4O12)-carbon composite has been synthesized and demonstrated as an electrode material for supercapacitors. The Fe2P4O12-carbon composite has been thoroughly characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, electron microscopy, etc. The composite shows predominant capacitive behaviour only in acidic medium; its charge storage properties are relatively poor in alkaline medium, indicating the important role of H+ in the charge storage mechanism. The composite shows a capacitance of 251 F g(-1) at a current density of 1 A g(-1). The composite is highly stable in 0.5 M H2SO4 and does not show any apparent capacitance loss after 9000 charge-discharge cycles recorded at a current density of 5 A g(-1).

1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/fe2p4o12-carbon-composite-highly-stable-electrode-material-electrochemical-capacitors02395nas a2200241 4500008004100000022001400041245009700055210006900152260000900221300001400230490000600244520158800250653001901838653002401857653001401881653003001895653002101925100002401946700001601970700001501986700002402001856012802025 2019 eng d a2196-021600aMedium modulated oxygen reduction activity of Fe/Co active centre-engrafted electrocatalysts0 aMedium modulated oxygen reduction activity of FeCo active centre cJUN  a2956-29640 v63 a

Iron and cobalt metal atoms are effective active centers for the synthesis of carbon-based noble-metal-free catalysts for the oxygen reduction reaction (ORR) owing to their cost-effective intrinsic activity and tunable properties. Annealing of the active center with the conducting carbon enhances the ORR activity significantly. Herein, we have engrafted Fe and Co active centers in the homemade conducting carbon and the ORR performance has been closely observed under acidic and basic pH conditions to understand the influence of the medium and participating moieties towards the performance. In the half-cell reaction, the onset potential and half-wave potential for ORR are governed by the surface intermediates and concomitantly driven by the adsorption energies of the intermediates over the active centers. The iron and cobalt active center-engrafted carbon catalyst behaves differently in acidic and basic electrolytes owing to the dissociation of the surface intermediates. The iron-based catalyst shows improved onset potential against the cobalt-based one. Similarly, the cobalt-based catalyst shows improved half-wave potential against the iron active-center-grafted catalyst. The combined synergistic effect of the two catalysts is realized in the composition represented as Fe/2Co-N-GVC, where improved onset and half-wave potentials are noted in basic medium. A significant variation in the activity of the catalyst is observed as the medium changes from acidic to basic and the effect is directly associated with the surface adsorption of the intermediates.

10aactive centers10ahalf-wave potential10aMechanism10aoxygen reduction reaction10atransition state1 aKashyap, Varchaswal1 aAnand, Aljo1 aSoni, Roby1 aSreekumar, Kurungot uhttps://library.ncl.res.in/content/medium-modulated-oxygen-reduction-activity-feco-active-centre-engrafted-electrocatalysts02021nas a2200253 4500008004100000022001400041245012600055210006900181260000900250300001400259490000600273520118000279653002001459653001001479653001901489653001901508653001601527100001501543700002801558700001501586700001901601700002401620856012301644 2019 eng d a2196-021600aSynthesis of ultrathin PEDOT on carbon nanotubes and shear thinning xanthan Gum-H2SO4 gel electrolyte for supercapacitors0 aSynthesis of ultrathin PEDOT on carbon nanotubes and shear thinn cMAR  a1861-18690 v63 a

Resistance of the electrode material play a vital role for applications in supercapacitors, where lowering the resistance leads to improved performance. Poly(3,4-ethylene dioxythiophene) (PEDOT) possesses high theoretical conductivity; however, the high density of grain boundaries, low accessible surface area, and low rate capability have been pervasive issues affecting the PEDOT-based supercapacitors. To this end, a hydrothermal method is proposed in this work where oxygen functional groups incorporated on the surface of carbon nanotubes (CNTs) are utilized to polymerize 3,4-ethylenedioxythiophene (EDOT). PEDOT forms an ultrathin, well-aligned coating on the surface of CNTs. This arrangement minimizes the number of grain boundaries and increases the electrochemically active surface area. Additionally, a shear-thinning Xanthan gum-H2SO4 gel electrolyte is introduced to overcome the low impregnation of the conventional polyvinyl-based electrolyte due to the hydrophobicity of the CNT-PEDOT composite. A supercapacitor based on this material showed a very low Equivalent Series Resistance (ESR) of 0.31 which leads to a high power density of 74 W cm(-3).

10agel electrolyte10aPEDOT10ashear thinning10asupercapacitor10axanthan gum1 aSoni, Roby1 aBhange, Siddheshwar, N.1 aAthira, E.1 aChetry, Rashmi1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/synthesis-ultrathin-pedot-carbon-nanotubes-and-shear-thinning-xanthan-gum-h2so4-gel02872nas a2200253 4500008004100000022001400041245010000055210006900155260000800224300001400232490000600246520202700252653002002279653002002299653001402319653003002333653001602363100002802379700001502407700001902422700002302441700002402464856013002488 2020 eng d a2574-097000aFeNx/FeSx-anchored carbon sheet-carbon nanotube composite electrocatalysts for oxygen reduction0 aFeNxFeSxanchored carbon sheetcarbon nanotube composite electroca cMAR a2234-22450 v33 a

Even though various Pt-free electrocatalysts for oxygen reduction reaction (ORR) have been introduced, many of them are found to be active only in alkaline conditions. Considering Nafion, phosphoric acid-doped polybenzimidazole (PBI), and so on as the prominent ionomer membranes, used in the commercially available polymer electrolyte membrane fuel cells (PEMFCs), it becomes important that any development on the Pt-free catalysts should ensure the better ORR performance under acidic conditions. The present work effectively tackles this issue, where an ORR-based catalyst could be prepared with simultaneous incorporation of both Fe-N and Fe-S active sites on in situ generated carbon sheets which are spatially separated by the carbon nanotube (CNT) network. This catalyst shows ability to perform under both acidic and basic conditions. This has been achieved by growing a polyethylenedioxythiophene polymer network in the presence of CNT and melamine followed by its pyrolysis under an inert atmosphere. The catalyst formed at 900 degrees C (PMCNT-900) displays 0.94 V onset potential for ORR under acidic electrolyte conditions, which corresponds to 60 mV overpotential compared to its 40 wt % Pt/C counterpart. Interestingly, in single cell demonstration of Nafion-based PEMFC with PMCNT-900 as the cathode catalyst, the system delivered a maximum power density (PD) of 500 and 275 mW/cm(2) at 60 degrees C under H-2-O-2 and H-2-air feed conditions, respectively. On the other hand, in a single cell test in the anion exchange membrane fuel cell (AEMFC) mode, a maximum power density of 65 mW/cm(2) at 50 degrees C could be achieved with the same cathode catalyst, which is a comparable value obtained while employing Pt/C as the cathode. These results, thus, infer to the efficiency of the catalyst to facilitate ORR under the extreme pH conditions, and particularly its performance under acidic condition reveals its prospect as a potential Pt-free electrocatalyst to serve in the Nafion-based systems.

10acarbon nanotube10aelectrocatalyst10afuel cell10aoxygen reduction reaction10aPt-free ORR1 aBhange, Siddheshwar, N.1 aSoni, Roby1 aSingla, Gourav1 aAjithkumar, T., G.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/fenxfesx-anchored-carbon-sheet-carbon-nanotube-composite-electrocatalysts-oxygen-reduction02844nas a2200241 4500008004100000022001400041245017400055210006900229260000800298300001400306490000600320520196200326653001602288653002002304653001402324653003002338653001902368100001802387700002802405700001502433700002402448856013002472 2020 eng d a2574-096200aWO3 nanorods bearing interconnected Pt nanoparticle units as an activity-modulated and corrosion-resistant carbon-free system for polymer electrolyte membrane fuel cells0 aWO3 nanorods bearing interconnected Pt nanoparticle units as an  cFEB a1908-19210 v33 a

Commercial platinum-supported carbon (Pt/C) catalyst is the most widely used oxygen reduction reaction (ORR) electrocatalyst in polymer electrolyte membrane fuel cells (PEMFCs). However, carbon oxidation in Pt/C during the operation of PEMFCs poses serious issues, particularly in meeting long-term durability of the cells. Although carbon-free Pt-based catalysts are considered to be the best alternatives, the single-cell performances reported for many such systems are found to be inferior to that of the carbon-based systems. As a practical way to realize a carbon-free electrocatalyst, we have developed a system by dispersing an interconnected Pt nanoparticle network on the nanorods of tungsten oxide (WO3). Uniform dispersion of the WO3 nanorods by fine and more or less interconnected Pt nanoparticles (20 wt %) is a key feature of the electrocatalyst. This has helped the system to achieve an intrinsic ORR characteristics which is very similar to that of Pt/C, as reflected from the comparative analysis of the onset potential, half-wave potential, limiting current density, and the number of electrons transferred in the ORR process. Pt/WO3 also shows better stability under start-stop accelerated potential cycling after 10 000 cycles, compared to Pt/C. The relative decrement in the electrochemically active surface area (ECSA) for Pt/WO3 nanorods was negligible, compared to the similar to 26% decrement registered by Pt/C under the identical testing conditions. Finally, a system-level validation in a single-cell model of PEMFC by fabricating a membrane electrode assembly (MEA) with Pt/WO3 as both the anode and cathode catalyst delivered comparable output power density as that of a similar system fabricated by using Pt/C. ECSA comparison in MEA shows the potential use of Pt/WO3-400 as the catalyst for the fuel cells, since it is exhibiting an ECSA value that is 3.4 greater than that of Pt/C at a Pt loading of 0.5 mg cm(-2).

10aCarbon-free10aelectrocatalyst10afuel cell10aoxygen reduction reaction10atungsten oxide1 aKumar, Sachin1 aBhange, Siddheshwar, N.1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/wo3-nanorods-bearing-interconnected-pt-nanoparticle-units-activity-modulated-and-corrosion02131nas a2200169 4500008004100000022001400041245010800055210006900163260000800232300001400240490000600254520151300260100001801773700001501791700002401806856013101830 2021 eng d a2398-490200aPdP/WO3 multi-functional catalyst with high activity and stability for direct liquid fuel cells (DLFCs)0 aPdPWO3 multifunctional catalyst with high activity and stability cSEP a4758-47700 v53 aDirect liquid fuel cells are energy conversion devices which utilize formate and methanol as fuels. These systems are relieved of the problem of H-2 transport and storage, making them highly desirable for various practical applications. However, the low stability and activity of carbon supported catalysts such as Pt/C both in the anode and cathode is a critical hindering factor towards their further development. As a practical solution to overcome this issue, in this work, we report on the development of phosphorus-doped palladium (PdP) nanoparticle-supported tungsten oxide (WO3) nanorods (PdP/WO3) as a versatile multifunctional catalyst for facilitating the oxidation of formate and methanol in the anode and the oxygen reduction reaction (ORR) in the cathode. Strong metal-support interactions and electronic modifications incurred by the doped phosphorus help this system to achieve desirable properties to enable it to effectively function both for the anode and cathode applications. PdP/WO3 showed 16-times higher mass activity compared to Pt/C even after 3000 start/stop cycles for the ORR. For formate and methanol oxidation, PdP/WO3 exhibited current densities of 0.50 and 0.734 A mg(Pd)(-1), respectively, outperforming the state-of-the-art catalysts. With these bifunctional features, PdP/WO3 stands out as a potential system to be used as an anode and cathode catalyst in direct liquid fuel cells, all the while offering an opportunity for the development of carbon-free electrocatalysts.1 aKumar, Sachin1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pdpwo3-multi-functional-catalyst-high-activity-and-stability-direct-liquid-fuel-cells-dlfcs02156nas a2200229 4500008004100000022001400041245014800055210006900203260000800272490000600280520131300286653003301599653001501632653003001647653002401677100001801701700002001719700002401739700001501763700002401778856012401802 2023 eng d a2366-748600aPt-anchored-zirconium phosphate nanoplates as high-durable carbon-free oxygen reduction reaction electrocatalyst for PEM fuel cell applications0 aPtanchoredzirconium phosphate nanoplates as highdurable carbonfr cFEB0 v73 a

Commercially available platinum-supported carbon (Pt/C) catalysts are the most widely used oxygen reduction reaction (ORR) electrocatalysts in polymer electrolyte membrane fuel cells (PEMFCs). However, inadequate active triple-phase boundary formation and carbon oxidation in Pt/C during PEMFC operation shorten its lifetime and efficiency. In this direction, a new class of carbon-free electrocatalysts for ORR is prepared by dispersing Pt nanoparticles on ZrP (Zirconium phosphates) nanoplates. In one case (ZrP@Pt), the Pt nanoparticles are found to be closely distributed and completely covering the ZrP nanoplates, whereas in the second case (Pt/ZrP), the Pt nanoparticles selectively restrict dispersion along the edges of the support. ZrP as the support displays an intrinsic proton conductivity of approximate to 0.5 x 10(-4) S cm(-1) at 70 degrees C, with an activation energy (E-a) of 0.19 eV. Pt/ZrP shows better durability after 3000 start-stop cycles. The mass activity of Pt/ZrP is increased by 4.6 times compared to Pt/C, which exhibits a loss in mass activity by 1.37 times. The single-cell level validation of ZrP@Pt, Pt/ZrP, and Pt/C as the electrocatalysts in PEMFC at an operating potential of 0.60 V shows the achievable current densities of 0.600, 0.890, and 0.890 A cm(-2).

10acarbon-free electrocatalysts10afuel cells10aoxygen reduction reaction10azirconium phosphate1 aKumar, Sachin1 aYoyakki, Athira1 aPandikassala, Ajmal1 aSoni, Roby1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/pt-anchored-zirconium-phosphate-nanoplates-high-durable-carbon-free-oxygen-reduction01697nas a2200193 4500008004100000022001400041245014800055210006900203260000800272300001500280490000700295520097600302100002101278700001501299700001801314700001901332700002301351856012901374 2025 eng d a2196-021600aHigh-performance polysulfide-trapping lithium sulfur battery cathode: cubic Co3O4 catalyst within a nitrogen-doped entangled graphene framework0 aHighperformance polysulfidetrapping lithium sulfur battery catho cFEB ae2024004880 v123 a

The cycling performance of lithium-sulfur (Li-S) batteries is hampered by polysulfide dissolution which impacts the overall performance of Li-S batteries. Here we report the synthesis and characterization of polysulfide trapping cathode material for Li-S batteries based on Co3O4 nanocubes supported within a nitrogen-doped entangled graphene (Co3O4/NEGF). The highly porous conductive graphene network is shown to facilitate fast electron transport and ion diffusion while the nitrogen dopants and polar Co3O4 offer both abundant active sites for polysulfide conversion while promoting intermediate polysulfide binding. The porous structure allows for high sulfur loading of 76.4 wt % (S@Co3O4/NEGF), while efficiently accommodating volumetric expansion during charge-discharge. The Co3O4/NEGF cathode composite exhibited a high specific capacity of 1143 mAh g-1 at a current density of C/20 and maintained a 79 % reversible capacity after 200 cycles at C/5.

1 aManna, Narugopal1 aSoni, Roby1 aYoung, R., S.1 aJervis, Rhodri1 aMiller, Thomas, S. uhttps://library.ncl.res.in/content/high-performance-polysulfide-trapping-lithium-sulfur-battery-cathode-cubic-co3o4-catalyst