02386nas a2200253   4500008004100000022001400041245008400055210006900139260007100208300001600279490000600295520147900301653002101780653002001801653002001821653001401841653003001855100002501885700002701910700002801937700002701965700002401992856011602016       2015                        eng d  a1944-824400aCarbon nanohorn-derived graphene nanotubes as a platinum-free fuel cell cathode0 aCarbon nanohornderived graphene nanotubes as a platinumfree fuel  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV  a24256-242640 v73 a<p>Current low-temperature fuel cell research mainly focuses on the development of efficient nonprecious electrocatalysts for the reduction of dioxygen molecule due to the reasons like exorbitant cost and scarcity of the current state-of-the-art Pt-based catalysts. As a potential alternative to such costly electrocatalysts, we report here the preparation of an efficient graphene nanotube based oxygen reduction electrocatalyst which has been derived from single walled nanohorns, comprising a thin layer of graphene nanotubes and encapsulated iron oxide nanopartides (FeGNT). FeGNT shows a surface area of 750 m(2)/g, which is the highest ever reported among the metal encapsulated nanotubes. Moreover, the graphene protected iron oxide nanoparticles assist the system to attain efficient distribution of Fe-N-x and quaternary nitrogen based active reaction centers, which provides better activity and stability toward the oxygen reduction reaction (ORR) in acidic as well as alkaline conditions. Single cell performance of a proton exchange membrane fuel cell by using FeGNT as the cathode catalyst delivered a maximum power density of 200 mW cm(-2) with Nafion as the proton exchange membrane at 60 degrees C. The facile synthesis strategy with iron oxide encapsulated graphitic carbon morphology opens up a new horizon of hope toward developing Pt-free fuel cells and metal-air batteries along with its applicability in other energy conversion and storage devices.</p>10acarbon nanohorns10acarbon nanotube10aelectrocatalyst10afuel cell10aoxygen reduction reaction1 aUnni, SreeKuttan, M.1 aIllathvalappil, Rajith1 aBhange, Siddheshwar, N.1 aPuthenpediakkal, Hasna1 aKurungot, Sreekumar  uhttps://library.ncl.res.in/content/carbon-nanohorn-derived-graphene-nanotubes-platinum-free-fuel-cell-cathode-002139nas 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-tetrapods