02927nas a2200325 4500008004100000245010200041210006900143260000800212490000600220520185800226653003302084653001302117653001202130653003002142653002002172653002502192653001802217653001402235653001002249653002102259653001602280653002002296653002002316653003902336100002302375700002902398700003002427700001802457856012602475 2017 eng d00aCopper Cobalt Sulfide Nanosheets Realizing a Promising Electrocatalytic Oxygen Evolution Reaction0 aCopper Cobalt Sulfide Nanosheets Realizing a Promising Electroca cSEP0 v73 a

Nanostructured CuCo2S4, a mixed metal thiospinel, is found to be a benchmark electrocatalyst for oxygen evolution reaction (OER) in this study with a low overpotential, a low Tafel slope, a high durability, and a high turnover frequency (TOF) at lower mass loadings. Nanosheets of CuCo2S4 are realized from a hydrothermal synthesis method in which the average thickness of the sheets is found to be in the range of 815 nm. Aggregated nanosheets form a highly open hierarchical structure. When used as an electrocatalyst, CuCo2S4 nanosheets offer an overpotential value of 310 mV at a 10 mA cm(2) current density, which remains consistent for 10000 measured cycles in a 1 M KOH electrolyte. A chronoamperometric study reveals constant oxygen evolution for 12 h at a 10 mV s(-1) scan rate without any degradation of the activity. Furthermore, the calculated mass activity of the CuCo2S4 electrocatalyst is found to be 14.29 A/g and to afford a TOF value of 0.1431 s(-1) at 310 mV at a mass loading of 0.7 mg cm(-2). For comparison, nanostructures of Co3S4 and Cu0.5Co2.5S4 have been synthesized using a similar method followed for CuCo2S4. When compared to the OER activities among these three thiospinels and standard IrO2, CuCo2S4 nanosheets offered the highest OER activities at the same mass loading (0.7 mg/cm(-2)). Extensive X-ray photoelectron spectroscopy and electron paramagnetic resonance analyses for a mechanistic study reveal that introduction of Cu into the Co3S4 lattice enhances the oxygen evolution and kinetics by offering Cu2+ sites for utilitarian adsorption of OH, O, and OOH reactive species and also by offering a highly active high-spin state of octahedral Co3+ for OER catalysis.

10aBifunctional Electrocatalyst10aCatalyst10aCuco2s410aEfficient Electrocatalyst10aelectrocatalyst10aElectronic-structure10aNanoparticles10aNanosheet10aoxide10aoxygen evolution10aperformance10aRecent Progress10aWater oxidation10aWater Splitting Hydrogen Evolution1 aChauhan, Meenakshi1 aReddy, Kasala, Prabhakar1 aGopinath, Chinnakonda, S.1 aDeka, Sasanka uhttps://library.ncl.res.in/content/copper-cobalt-sulfide-nanosheets-realizing-promising-electrocatalytic-oxygen-evolution02139nas 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-phase