03237nas a2200181 4500008004100000022001400041245014900055210006900204260011000273300001400383490000600397520241500403100002902818700003002847700002702877700002402904856012702928 2014 eng d a1754-569200aNanoporous graphene by quantum dots removal from graphene and its conversion to a potential oxygen reduction electrocatalyst via nitrogen doping0 aNanoporous graphene by quantum dots removal from graphene and it aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR a1059-10670 v73 a

A simple way to produce an efficient metal-free oxygen reduction electrocatalyst from graphene by generating nanopores in the matrix and subsequently establishing nitrogen-doped active sites along the pore openings is demonstrated. Well-structured nanoporous graphene (pGr) and photoluminescent graphene quantum dots (GQDs) could be simultaneously generated by a chemically assisted oxidative treatment of graphene. The process helped to knock out small pieces of Gr through epoxide formation, which subsequently resulted in the generation of GQD and pGr simultaneously. A longer oxidation time increased the quantity of GQDs and also resulted in a higher photoluminescent (PL) quantum yield. The PL quantum yield of GQD formed after 72 h of the oxidative treatment (GQD-72) was 15.8%, which is greater than the previous reported values. The TEM images showed matching sizes for GQDs and the pores present in pGr, implying that the pores are generated by the removal of GQDs from graphene during the oxidative treatment. Since pore openings are expected to give higher levels of unsaturation and defect sites in the system and are thus being treated as fertile regions for heteroatom doping, pGr-72 was further subjected to nitrogen (NpGr-72). NpGr-72 displayed excellent activity towards the electrochemical oxygen reduction reaction (ORR) compared to nitrogen-doped non-porous graphene (NGr) and many other reported nitrogen-doped carbon materials. A distinct 50 mV gain in the overpotential and 2.5 times increment in the kinetic current density (j(k)) have been achieved in the case of NpGr-72 compared to NGr. Interestingly, unlike NGr, NpGr-72 effectively reduced the oxygen molecule with a greater involvement of the preferred four-electron pathway. Additionally, the overpotential difference of NpGr-72 with respect to 20 wt% Pt/C is only 60 mV. Additionally, in a single cell evaluation under anion exchange membrane fuel cell (AEMFC) conditions, NpGr-72 exhibited a maximum power density of 27 mW cm(-2), which is significantly higher than the corresponding value of 10 mW cm(-2) obtained for NGr. Thus, the overall enhancement in the performance characteristics of NpGr-72 is attributed to the higher content of nitrogen (7.8 wt%) and its large proportion of desired chemical environment, which could be established by utilizing the high level of carbon unsaturation around the pore openings.

1 aPalaniselvam, Thangavelu1 aValappil, Manila, Ozhukil1 aIllathvalappil, Rajith1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nanoporous-graphene-quantum-dots-removal-graphene-and-its-conversion-potential-oxygen-002351nas a2200193 4500008004100000022001400041245011700055210006900172260011000241300001600351490000600367520155200373100002401925700002401949700001801973700001801991700002402009856012402033 2014 eng d a2040-336400aNitrogen-doped graphene interpenetrated 3D Ni-nanocages: efficient and stable water-to-dioxygen electrocatalysts0 aNitrogendoped graphene interpenetrated 3D Ninanocages efficient  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a13179-131870 v63 a

Herein, we report the synthesis of a nitrogen-doped graphene (NGr) interpenetrated 3D Ni-nanocage (Ni-NGr) electrocatalyst by a simple water-in-oil (w/o) emulsion technique for oxidation of water to dioxygen. Correlation of adsorption of NGr and subsequent interpenetration through the specific surface plane of nickel particles as well as the concomitant interaction of N and C with Ni in the nano-regime has been investigated. Apart from the benefits of the synergistic interactions between Ni, N, and C, the overall integrity of the structure and its intra-molecular connectivity within the framework help in achieving better oxygen evolution characteristics at a significantly reduced overpotential. The engineered Ni-NGr nanocage displays a substantially low overpotential of similar to 290 mV at a practical current density of 20 mA cm(-2) in 0.1 M KOH. In comparison, NGr and Ni-particles as separate entities give overpotentials of similar to 570 and similar to 370 mV under similar conditions. Moreover, the long term stability of Ni-NGr was investigated by anodic potential cycling for 500 cycles and an 8.5% increment in the overpotential at 20 mA cm(-2) was observed. Additionally, a chronoamperometric test was performed for 15 h at 20 mA cm(-2), which highlights the better sustainability of Ni-NGr under the actual operating conditions. Finally, the quantitative estimation of evolved oxygen was monitored by gas chromatography and was found to be 70 mmol h(-1) g(-1) of oxygen, which is constant in the second cycle as well.

1 aDhavale, Vishal, M.1 aGaikwad, Sachin, S.1 aGeorge, Leena1 aDevi, Nandini1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nitrogen-doped-graphene-interpenetrated-3d-ni-nanocages-efficient-and-stable-water-003101nas a2200193 4500008004100000022001400041245014400055210006900199260011000268300001600378490000600394520226300400100002402663700002302687700002002710700002402730700002402754856012902778 2015 eng d a2040-336400aNanocrystalline Fe-Fe2O3 particle-deposited N-doped graphene as an activity-modulated Pt-free electrocatalyst for oxygen reduction reaction0 aNanocrystalline FeFe2O3 particledeposited Ndoped graphene as an  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT a20117-201250 v73 a

The size-controlled growth of nanocrystalline Fe-Fe2O3 particles (2-3 nm) and their concomitant dispersion on N-doped graphene (Fe-Fe2O3/NGr) could be attained when the mutually assisted redox reaction between NGr and Fe3+ ions could be controlled within the aqueous droplets of a water-in-oil emulsion. The synergistic interaction existing between Fe-Fe2O3 and NGr helped the system to narrow down the overpotential for the oxygen reduction reaction (ORR) by bringing a significant positive shift to the reduction onset potential, which is just 15 mV higher than its Pt-counterpart. In addition, the half-wave potential (E-1/2) of Fe-Fe2O3/NGr is found to be improved by a considerable amount of 135 mV in comparison to the system formed by dispersing Fe-Fe2O3 nanoparticles on reduced graphene oxide (Fe-Fe2O3/RGO), which indicates the presence of a higher number of active sites in Fe-Fe2O3/NGr. Despite this, the ORR kinetics of Fe-Fe2O3/NGr are found to be shifted significantly to the preferred 4-electron-transfer pathway compared to NGr and Fe-Fe2O3/RGO. Consequently, the H2O2% was found to be reduced by 78.3% for Fe-Fe2O3/NGr (13.0%) in comparison to Fe-Fe2O3/RGO (51.2%) and NGr (41.0%) at -0.30 V (vs. Hg/HgO). This difference in the yield of H2O2 formed between the systems along with the improvements observed in terms of the oxygen reduction onset and E-1/2 in the case of Fe-Fe2O3/NGr reveals the activity modulation achieved for the latter is due to the coexistence of factors such as the presence of the mixed valancies of iron nanoparticles, small size and homogeneous distribution of Fe-Fe2O3 nanoparticles and the electronic modifications induced by the doped nitrogen in NGr. A controlled interplay of these factors looks like worked favorably in the case of Fe-Fe2O3/NGr. As a realistic system level validation, Fe-Fe2O3/NGr was employed as the cathode electrode of a single cell in a solid alkaline electrolyte membrane fuel cell (AEMFC). The system could display an open circuit voltage (OCV) of 0.73 V and maximum power and current densities of 54.40 mW cm(-2) and 200 mA cm(-2), respectively, which are comparable to the performance characteristics of a similar system derived by using 40 wt% Pt/C as the cathode electrode.

1 aDhavale, Vishal, M.1 aSingh, Santosh, K.1 aNadeema, Ayasha1 aGaikwad, Sachin, S.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nanocrystalline-fe-fe2o3-particle-deposited-n-doped-graphene-activity-modulated-pt-free-002284nas a2200205 4500008004100000022001400041245019700055210006900252260000900321300001200330490000700342520145200349100002501801700002801826700002701854700001901881700002401900700002401924856013001948 2015 eng d a1613-681000aNitrogen-induced surface area and conductivity modulation of carbon nanohorn and its function as an efficient metal-free oxygen reduction electrocatalyst for anion-exchange membrane fuel cells0 aNitrogeninduced surface area and conductivity modulation of carb cJAN  a352-3600 v113 a

Nitrogen-doped carbon morphologies have been proven to be better alternatives to Pt in polymer-electrolyte membrane (PEM) fuel cells. However, efficient modulation of the active sites by the simultaneous escalation of the porosity and nitrogen doping, without affecting the intrinsic electrical conductivity, still remains to be solved. Here, a simple strategy is reported to solve this issue by treating single-walled carbon nanohorn (SWCNH) with urea at 800 degrees C. The resulting nitrogen-doped carbon nanohorn shows a high surface area of 1836 m(2) g(-1) along with an increased electron conductivity, which are the pre-requisites of an electro catalyst. The nitrogen-doped nanohorn annealed at 800 degrees C (N-800) also shows a high oxygen reduction activity (ORR). Because of the high weight percentage of pyridinic nitrogen coordination in N-800, the present catalyst shows a clear 4-electron reduction pathway at only 50 mV overpotential and 16 mV negative shift in the half-wave potential for ORR compared to Pt/C along with a high fuel selectivity and electrochemical stability. More importantly, a membrane electrode assembly (MEA) based on N-800 provides a maximum power density of 30 mW cm(-2) under anion-exchange membrane fuel cell (AEMFC) testing conditions. Thus, with its remarkable set of physical and electrochemical properties, this material has the potential to perform as an efficient Pt-free electrode for AEMFCs.

1 aUnni, SreeKuttan, M.1 aBhange, Siddheshwar, N.1 aIllathvalappil, Rajith1 aMutneja, Nisha1 aPatil, Kasinath, R.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nitrogen-induced-surface-area-and-conductivity-modulation-carbon-nanohorn-and-its-function02299nas a2200253 4500008004100000022001400041245014600055210006900201260007500270300001400345490000700359520131800366653002001684653002001704653003001724653002001754653001701774100002901791700002401820700002601844700002001870700002401890856013101914 2016 eng d a1616-301X00aNanoporous graphene enriched with Fe/Co-N active sites as a promising oxygen reduction electrocatalyst for anion exchange membrane fuel cells0 aNanoporous graphene enriched with FeCoN active sites as a promis aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a2150-21620 v263 a

Here, a simple but efficient way is demonstrated for the preparation of nanoporous graphene enriched with Fe/Co-nitrogen-doped active sites (Fe/Co-NpGr) as a potential electrocatalyst for the electrochemical oxygen reduction reaction (ORR) applications. Once graphene is converted into porous graphene (pGr) by a controlled oxidative etching process, pGr can be converted into a potential electrocatalyst for ORR by utilizing the created edge sites of pGr for doping nitrogen and subsequently to utilize the doped nitrogens to build Fe/Co coordinated centers (Fe/Co-NpGr). The structural information elucidated using both XPS and TOF-SIMS study indicates the presence of coordination of the M-N (M = Fe and Co)-doped carbon active sites. Creation of this bimetallic coordination assisted by the nitrogen locked at the pore openings is found to be helping the system to substantially reduce the overpotential for ORR. A 30 mV difference in the overpotential () with respect to the standard Pt/C catalyst and high retention in half wave potential after 10 000 cycles in ORR can be attained. A single cell of an anion exchange membrane fuel cell (AEMFC) by using Fe/Co-NpGr as the cathode delivers a maximum power density of approximate to 35 mWcm(-2) compared to 60 mWcm(-2) displayed by the Pt-based system.

10aelectrocatalyst10anitrogen doping10aoxygen reduction reaction10aporous grapheme10aquantum dots1 aPalaniselvam, Thangavelu1 aKashyap, Varchaswal1 aBhange, Siddeswar, N.1 aBaek, Jong-Beom1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nanoporous-graphene-enriched-feco-n-active-sites-promising-oxygen-reduction-electrocatalyst02769nas a2200169 4500008004100000022001400041245014000055210006900195260011000264300001400374490000600388520199700394100002802391700002502419700002402444856013102468 2016 eng d a2050-748800aNitrogen and sulphur co-doped crumbled graphene for the oxygen reduction reaction with improved activity and stability in acidic medium0 aNitrogen and sulphur codoped crumbled graphene for the oxygen re aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR a6014-60200 v43 a

Non-precious dioxygen reduction electrocatalysts have attracted great attention nowadays for the development of stable, cost-effective proton exchange membrane fuel cells. In line with the development of non-precious electrocatalysts, here we report the synthesis of a platinum-free oxygen reduction electrocatalyst based on nitrogen and sulphur co-doped crumbled graphene with trace amounts of iron. The co-doped crumbled graphene structure was obtained by simple oxidative polymerisation of ethylenedioxythiophene in aqueous solution followed by an annealing process under an inert atmosphere. This new electrocatalyst displays improved oxygen reduction activity and electrochemical stability under acidic conditions. The half-cell reaction of the 1000 degrees C annealed polyethylenedioxythiophene (PF-1000) displays only 0.1 V overpotential in both the onset and half-wave potentials compared to state-of-the-art Pt/C in an acidic environment for the ORR. More importantly, the limiting current of PF-1000 clearly surpasses the limiting current displayed by Pt/C, indicating that the crumbled assembly of the graphene flakes helps the system to expose the active sites and the porous network of the material matrix ensures extended accessibility of active sites to the electrolyte and reagent. The dioxygen reduction kinetics of PF-1000 appear similar to those of Pt/C and the system accomplishes the reduction of the dioxygen molecule through the recommended four-electron reduction pathway. The improved activity and electrochemical stability of PF-1000 are mainly attributed to the enriched and well accessible active reaction centres such as graphitic nitrogen, sulphur, and iron coordination and the peculiar morphology of PF-1000. Further, a single cell evaluation of a membrane electrode assembly based on PF-1000 as the cathode catalyst delivered a maximum power density of 193 mW cm(-2) at a cell temperature of 60 degrees C using Nafion as the proton conducting membrane.

1 aBhange, Siddheshwar, N.1 aUnni, SreeKuttan, M.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nitrogen-and-sulphur-co-doped-crumbled-graphene-oxygen-reduction-reaction-improved-activity00721nas a2200181 4500008004100000022001500041245014300056210006900199260000800268300001600276490000600292100002400298700002300322700002000345700002400365700002400389856012600413 2017 eng d a 2040-336400aNanocrystalline Fe-Fe2O3 particledeposited N-doped graphene as an activity-modulated Pt-free electrocatalyst for oxygen reduction reaction0 aNanocrystalline FeFe2O3 particledeposited Ndoped graphene as an  cSEP a13341-133420 v91 aDhavale, Vishal, M.1 aSingh, Santosh, K.1 aNadeema, Ayasha1 aGaikwad, Sachin, S.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nanocrystalline-fe-fe2o3-particledeposited-n-doped-graphene-activity-modulated-pt-free02740nas a2200169 4500008004100000245019800041210006900239260000800308300001400316490000600330520200500336100002702341700002402368700002802392700002402420856012602444 2017 eng d00aNitrogen-doped graphene anchored with mixed growth patterns of CuPt alloy nanoparticles as a highly efficient and durable electrocatalyst for the oxygen reduction reaction in an alkaline medium0 aNitrogendoped graphene anchored with mixed growth patterns of Cu cJUL a9009-90170 v93 a

A highly active and durable CuPt alloy catalyst with trigonal bipyramidal and truncated cube-type mixed morphologies, anchored on the nitrogen-doped graphene (NGr) surface (CuPt-TBTC/NGr), was prepared by a simple and fast method. The obtained CuPt alloy showed improved oxygen reduction reaction (ORR) activity, with a 30 mV positive shift in the half-wave potential value, as compared to the state-of-the-art Pt/C catalyst in a 0.1 M KOH solution. The CuPt alloy with the trigonal bipyramidal morphology possesses porous type inter-connected sides, which help to achieve improved mass transport of oxygen during the ORR. The exposure of the (111) plane of the CuPt alloy further improved the catalytic activity towards the dioxygen reduction in alkaline media. The ORR activity of the NGr-supported CuPt alloy was found to be dependent on the reaction time, and improved activity was obtained on the material derived at a reaction time of 90 min (CuPt-TBTC/NGr-90). The material synthesized at a lower or higher reaction time than 90 min resulted in a partially formed trigonal bipyramidal morphology with more truncated cubes or agglomerated trigonal bipyramidal and truncated cubes with closed type structures, respectively. Along with the high intrinsic ORR activity, CuPt-TBTC/NGr-90 displayed excellent electrochemical stability. Even after repeated 1000 potential cycling in a window ranging from 0.10 to 1.0 V (vs. RHE), the system clearly outperformed the state-of-the-art Pt/C catalyst with 15 and 60 mV positive shifts in the onset and half-wave potentials, respectively. CuPt-TBTC/NGr-90 also exhibited 2.1 times higher mass activity and 2.2 times higher specific activity, compared to Pt/C at 0.90 V (vs. RHE). Finally, a zinc-air battery fabricated with the alloy catalyst as the air electrode displayed a peak power density of 300 mW cm(-2), which is much higher than the peak power density of 253 mW cm(-2) obtained for the state-of-the-art Pt/C catalyst as the air electrode.

1 aIllathvalappil, Rajith1 aDhavale, Vishal, M.1 aBhange, Siddheshwar, N.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nitrogen-doped-graphene-anchored-mixed-growth-patterns-cupt-alloy-nanoparticles-highly02139nas a2200253 4500008004100000022001400041245016900055210006900224260000800293300001400301490000600315520119100321653001901512653003001531653002001561653003201581653002801613100002801641700002501669700001801694700002101712700002401733856012801757 2017 eng d a2196-021600aNitrogen-doped graphene with a three-dimensional architecture assisted by carbon nitride tetrapods as an efficient metal-free electrocatalyst for hydrogen evolution0 aNitrogendoped graphene with a threedimensional architecture assi cOCT a2643-26520 v43 aCurrent polymer membrane-based electrolyzers use Pt as a cathode catalyst for efficient reduction of water. The high cost of Pt-based catalysts forces researchers to develop alternative electrocatalysts. Here, a simple strategy has been proposed to synthesize a metal-free electrocatalyst for the hydrogen evolution reaction (HER) by high-temperature annealing of graphene oxide-coated melamine foam. The prepared catalyst possesses both structural and functional advantages with its three-dimensional (3D) interconnected arms of carbon nitride (CNx) backbone wrapped with nitrogen-doped graphene (N-RGO) sheets (CNx@N-RGO). CNx@N-RGO faces only a 193 mV overpotential to achieve a current density of 10mAcm(-2), which is far superior to the previously reported Pt-free systems. Along with the high exchange current density 34.7 x 10(-6)A cm(-2) and low Tafel slope of 54 mV dec(-1), CNx@N-RGO follows a Volmer-Heyrovsky mechanism for the HER. DFT calculations show that the synergy between CNx and N-RGO facilitates good electrical coupling between the two moieties and provides optimal binding to H+ ions on the catalyst that, in turn, results in efficient reduction of hydrogen ions.10acarbon nitride10aDensity functional theory10aelectrocatalyst10ahydrogen evolution reaction10anitrogen doped graphene1 aGangadharan, Pranav, K.1 aUnni, SreeKuttan, M.1 aKumar, Nandha1 aGhosh, Prasenjit1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nitrogen-doped-graphene-three-dimensional-architecture-assisted-carbon-nitride-tetrapods02139nas a2200289 4500008004100000022001400041245016200055210006900217260000800286300001600294490000600310520116500316653001401481653003001495653001301525653001001538653002101548653001001569653003001579653001601609653001601625653000901641100002001650700002401670700002401694856013101718 2017 eng d a2040-336400aNiZn double hydroxide nanosheet-anchored nitrogen-doped graphene enriched with the gamma-NiOOH phase as an activity modulated water oxidation electrocatalyst0 aNiZn double hydroxide nanosheetanchored nitrogendoped graphene e cSEP a12590-126000 v93 a

Herein, we report a facile solvothermal process to synthesize an active electrocatalyst for the oxygen evolution reaction (OER) in an alkaline medium by anchoring nanosheets of a NiZn double hydroxide over nitrogen doped reduced graphene oxide after enriching the system with the γ-NiOOH phase. This catalyst possesses a thin, porous and open layered structure, which makes the system more efficient and accessible for a better electrochemical water oxidation reaction. Moreover, we experimentally demonstrated that incorporation of Zn via a single-step solvothermal method provides an easy approach to obtain plenty of exposed γ-NiOOH phases to make the system more viable for OER with a small overpotential of 290 mV at 10 mA cm−2 and a Tafel slope of 44 mV per decade. In addition to this, the oxophilic nature of Zn in the (Zn)Ni-LDH/N-rGO catalyst helps to improve the long-term stability of the whole system. The obtained results open up possibilities for the design of future robust OER electrocatalysts by the use of very cheap and abundant materials like Ni and Zn in place of expensive Ir and Ru in the present commercial electrocatalysts.

10acatalysis10aEfficient Electrocatalyst10akinetics10aMetal10aNickel-Hydroxide10aoxide10aOxygen Evolution Reaction10aperformance10aXPS Spectra10azinc1 aNadeema, Ayasha1 aDhavale, Vishal, M.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nizn-double-hydroxide-nanosheet-anchored-nitrogen-doped-graphene-enriched-gamma-niooh-phase02108nas 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-stable02139nas a2200217 4500008004100000245014400041210006900185260000800254300001300262490000800275520132900283100002201612700001701634700002901651700001801680700002301698700002401721700002301745700002201768856013101790 2018 eng d00aNucleic aptamer modified porous reduced graphene oxide/MoS2 based electrodes for viral detection: application to human papillomavirus (HPV)0 aNucleic aptamer modified porous reduced graphene oxideMoS2 based cJUN a991-10000 v2623 aNext to graphene nanomaterials, molybdenum disulfide (MoS2) offers large surface area that can enhance its biosensing performance. In this work, we investigate the performance of glassy carbon (GC) electrodes modified successively with porous reduced graphene oxide (prGO) and molybdenum sulfide (MoS2) for the sensitive and selective detection of the L1-major capsid protein of human papilloma virus (HPV). Owing to the difficulties to perform serological assays and HPV culture efficiently, tools based on molecular recognition are becoming of great importance. We developed here an electrochemical sensor for HPV upon covalent functionalization of the electrode with an aptamer Sc5-c3, a RNA aptamer targeted against the HPV-16 L1 protein. Using differential pulse voltammetry (DPV) and an optimized sensor interface, a linear relationship between the peak current density of a redox couple such as [Fe(CN)6]4- and the concentration of HPV-16 L1 proteins in the range of 0.2-2 ng mL(-1) (3.5 pM-35.3 pM) could be reached with a detection limit of 0.1 ng mL(-1) (1.75 pM). Cross-reactivity studies demonstrated high selectivity over potential interfering species such as HPV-16 E6, opening new opportunities of the developed concept for the development of point of care devices. (C) 2018 Elsevier B.V. All rights reserved.1 aChekin, Fereshteh1 aBagga, Komal1 aSubramanian, Palaniappan1 aJijie, Roxana1 aSingh, Santosh, K.1 aKurungot, Sreekumar1 aBoukherroub, Rabah1 aSzunerits, Sabine uhttps://library.ncl.res.in/content/nucleic-aptamer-modified-porous-reduced-graphene-oxidemos2-based-electrodes-viral-detection02159nas a2200265 4500008004100000022001400041245010600055210006900161260000900230300001400239490000600253520124100259653002901500653002201529653002501551653002201576653000901598653002901607653003301636100001701669700002701686700002501713700002401738856013101762 2020 eng d a2168-048500aNafion lonomer-based single component electrolytes for aqueous Zn/MnO2 batteries with long cycle life0 aNafion lonomerbased single component electrolytes for aqueous Zn cAPR  a5040-50490 v83 a

Recently, aqueous rechargeable Zn/MnO2 batteries are emerging as promising energy storage aids owing to their improved safety, low cost of fabrication, and high energy density. However, the rapid decay of capacity during extended charge- discharge cycles hinders the prospect of this technology beyond lab-scale. In the conventional Zn/MnO2 cell, additives such as Mn2+ have been used to tackle the stability issue. Here, we demonstrate that cycling performance of the Zn/MnO2 cell can be improved substantially by using Nafion ionomer as the separator in combination with zinc-ion conducting electrolytes. The Nafion ionomer-based Zn/MnO2 cells do not require any Mn' additive in the electrolyte and hence termed as ``single component'' electrolytes. The postmortem study of the post-cycled electrodes reveals that the structural evolution of both the anode and cathode in various electrolytes (1 M Zn(CF3SO3)(2), 1 M ZnSO4 center dot 7H(2)O, and 3 M ZnSO4 center dot 7H(2)O) during prolonged cycling significantly influences the cycle life of the respective cells. Optimizing the Nafion ionomer membrane with a suitable electrolyte could render the desired combination of high capacity and high cycle life for a Zn/MnO2 cell.

10aaqueous Zn-ion batteries10aCycling stability10adendrite suppression10aElectrodeposition10aMnO210aNafion ionomer separator10asingle component electrolyte1 aGhosh, Meena1 aVijayakumar, Vidyanand1 aAnothumakkool, Bihag1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nafion-lonomer-based-single-component-electrolytes-aqueous-znmno2-batteries-long-cycle-life01900nas a2200181 4500008004100000022001400041245012300055210006900178260000900247300001400256490000600270520122500276100002101501700002001522700002301542700002401565856012901589 2020 eng d a2516-023000aNiFe layered double hydroxide-decorated N-doped entangled-graphene framework: a robust water oxidation electrocatalyst0 aNiFe layered double hydroxidedecorated Ndoped entangledgraphene  cAPR  a1709-17170 v23 a

Three dimensional (3D) porous carbon materials are highly desirable for electrochemical applications owing to their high surface area and porosity. Uniformly distributed porosity in the 3D architecture of carbon support materials allows reactant molecules to access more electrochemically active centres and simultaneously facilitate removal of the product formed during electrochemical reactions. Herein, we have prepared a nitrogen-doped entangled graphene framework (NEGF), decorated with NiFe-LDH nanostructures by an in situ solvothermal method followed by freeze-drying at high vacuum pressure and low temperature. The freeze-drying method helped to prevent the restacking of the graphene sheets and the formation of a high surface area nitrogen-doped entangled graphene framework (NEGF) supported NiFe-LDHs. The incorporation of the NEGF has significantly reduced the overpotential for the electrochemical oxygen evolution reaction (OER) in 1 M KOH solution. This corresponds to an overpotential reduction from 340 mV for NiFe-LDHs to 290 mV for NiFe-LDH/NEGF to reach the benchmark current density of 10 mA cm(-2). The preparation of the catalyst is conceived through a low-temperature scalable process.

1 aManna, Narugopal1 aAyasha, Nadeema1 aSingh, Santosh, K.1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/nife-layered-double-hydroxide-decorated-n-doped-entangled-graphene-framework-robust-water02136nas a2200193 4500008004100000022001400041245009500055210006900150260000900219300001400228490000700242520146600249100001701715700002701732700001801759700001901777700002401796856012201820 2021 eng d a1477-922600aNaphthalene dianhydride organic anode for a `rocking-chair' zinc-proton hybrid ion battery0 aNaphthalene dianhydride organic anode for a rockingchair zincpro cMAR  a4237-42430 v503 a

Rechargeable batteries consisting of a Zn metal anode and a suitable cathode coupled with a Zn2+ ion-conducting electrolyte are recently emerging as promising energy storage devices for stationary applications. However, the formation of high surface area Zn (HSAZ) architectures on the metallic Zn anode deteriorates their performance upon prolonged cycling. In this work, we demonstrate the application of 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTCDA), an organic compound, as a replacement for the Zn-metal anode enabling the design of a `rocking-chair' zinc-proton hybrid ion battery. The NTCDA electrode material displays a multi-plateau redox behaviour, delivering a specific discharge capacity of 143 mA h g(-1) in the potential window of 1.4 V to 0.3 V vs. Zn|Zn2+. The detailed electrochemical characterization of NTCDA in various electrolytes (an aqueous solution of 1 M ZnOTF, an aqueous solution of 0.01 M H2SO4, and an organic electrolyte of 0.5 M ZnOTF/acetonitrile) reveals that the redox processes leading to charge storage involve a contribution from both H+ and Zn2+. The performance of NTCDA as an anode is further demonstrated by pairing it with a MnO2 cathode, and the resulting MnO2||NTCDA full-cell (zinc-proton hybrid ion battery) delivers a specific discharge capacity of 41 mA h g(total)(-1) (normalized with the total mass-loading of both anode and cathode active materials) with an average operating voltage of 0.80 V.

1 aGhosh, Meena1 aVijayakumar, Vidyanand1 aKurian, Maria1 aDilwale, Swati1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/naphthalene-dianhydride-organic-anode-rocking-chair-zinc-proton-hybrid-ion-battery