03100nas a2200193   4500008004100000022001400041245014400055210006900199260011000268300001600378490000600394520226300400100002402663700002302687700002002710700002402730700002402754856012802778       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<p>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.</p>1 aDhavale, Vishal, M.1 aSingh, Santosh, K.1 aNadeema, Ayasha1 aGaikwad, Sachin, S.1 aKurungot, Sreekumar  uhttp://library.ncl.res.in/content/nanocrystalline-fe-fe2o3-particle-deposited-n-doped-graphene-activity-modulated-pt-free-000720nas a2200181   4500008004100000022001500041245014300056210006900199260000800268300001600276490000600292100002400298700002300322700002000345700002400365700002400389856012500413       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  uhttp://library.ncl.res.in/content/nanocrystalline-fe-fe2o3-particledeposited-n-doped-graphene-activity-modulated-pt-free02138nas a2200289   4500008004100000022001400041245016200055210006900217260000800286300001600294490000600310520116500316653001401481653003001495653001301525653001001538653002101548653001001569653003001579653001601609653001601625653000901641100002001650700002401670700002401694856013001718       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<p>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.</p>10acatalysis10aEfficient Electrocatalyst10akinetics10aMetal10aNickel-Hydroxide10aoxide10aOxygen Evolution Reaction10aperformance10aXPS Spectra10azinc1 aNadeema, Ayasha1 aDhavale, Vishal, M.1 aKurungot, Sreekumar  uhttp://library.ncl.res.in/content/nizn-double-hydroxide-nanosheet-anchored-nitrogen-doped-graphene-enriched-gamma-niooh-phase