02175nas a2200253 4500008004100000022001400041245011500055210006900170260008000239300001400319490000800333520125000341653002001591653002101611653001901632653000901651653002601660653001201686100002501698700001801723700001901741700003001760856013101790 2008 eng d a1618-264200aImaging the stomatal physiology of somatic embryo-derived peanut leaves by scanning electrochemical microscopy0 aImaging the stomatal physiology of somatic embryoderived peanut  aTIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANYbSPRINGER HEIDELBERGcJUL a2227-22330 v3913 a

The stomatal physiology, chlorophyll distribution and photosynthetic activity of somatic embryo (SE)- and seedling-derived peanut plants grown in vitro (test tube-grown) and extra vitrum (soil-grown) are investigated using scanning electrochemical microscopy (SECM). This SECM imaging is performed in two different feedback modes, corresponding to oxygen evolution and chlorophyll distribution. More specifically, the oxygen evolution profiles of the in vitro leaves indicate important differences in leaf anatomy between the SE- and seedling-derived leaves. On the other hand, the chlorophyll distribution images show individual stomata of size ca. 27 +/- 5 mu m. Further studies on senescing (aged) leaves reveal interesting voltammograms that vary widely over the stomatal complexes and the surrounding tissues, probably due to the release of electroactive metabolites during chlorophyll breakdown when the leaves turn yellow. Thus, the present investigation could open up new opportunities for characterizing botanical systems using electroanalytical techniques. In addition, it could provide further insights into various areas of current relevance, including signal transduction, cell fate/differentiation and developmental biology.

10aleaf senescence10aoxygen evolution10aphotosynthesis10aSECM10asomatic embryogenesis10astomata1 aParthasarathy, Meera1 aSingh, Shweta1 aHazra, Sulekha1 aPillai, Vijayamohanan, K. uhttps://library.ncl.res.in/content/imaging-stomatal-physiology-somatic-embryo-derived-peanut-leaves-scanning-electrochemical-002927nas 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-evolution02910nas a2200265 4500008004100000022001400041245014100055210006900196260000900265300001400274490000700288520197300295653001902268653002102287653002302308653002802331653002102359100002702380700002402407700002702431700002102458700001802479700002402497856012302521 2020 eng d a0947-653900aHierarchical nanoflower arrays of Co9S8-Ni3S2 on nickel foam: a highly efficient binder-free electrocatalyst for overall water splitting0 aHierarchical nanoflower arrays of Co9S8Ni3S2 on nickel foam a hi cJUN  a7900-79110 v263 a

Hydrogen production is vital for meeting future energy demands and managing environmental sustainability. Electrolysis of water is considered as the suitable method for H-2 generation in a carbon-free pathway. Herein, the synthesis of highly efficient Co9S8-Ni3S2 based hierarchical nanoflower arrays on nickel foam (NF) is explored through the one-pot hydrothermal method (Co9S8-Ni3S2/NF) for overall water splitting applications. The nanoflower arrays are self-supported on the NF without any binder, possessing the required porosity and structural characteristics. The obtained Co9S8-Ni3S2/NF displays high hydrogen evolution reaction (HER), as well as oxygen evolution reaction (OER), activities in 1 m KOH solution. The overpotentials exhibited by this system at 25 mA cm(-2) are nearly 277 and 102 mV for HER and OER, respectively, in 1 m KOH solution. Subsequently, the overall water splitting was performed in 1 m KOH solution by employing Co9S8-Ni3S2/NF as both the anode and cathode, where the system required only 1.49, 1.60, and 1.69 V to deliver the current densities of 10, 25, and 50 mA cm(-2), respectively. Comparison of the activity of Co9S8-Ni3S2/NF with the state-of-the-art Pt/C and RuO2 coated on NF displays an enhanced performance for Co9S8-Ni3S2/NF both in the half-cell as well as in the full cell, emphasizing the significance of the present work. The post analysis of the material after water electrolysis confirms that the surface Co(OH)(2) formed during the course of the reaction serves as the favorable active sites. Overall, the activity modulation achieved in the present case is attributed to the presence of the open-pore morphology of the as formed nanoflowers of Co9S8-Ni3S2 on NF and the simultaneous presence of the surface Co(OH)(2) along with the highly conducting Co9S8-Ni3S2 core, which facilitates the adsorption of the reactants and subsequently its conversion into the gaseous products during water electrolysis.

10acobalt sulfide10aelectrocatalysts10aHydrogen evolution10aoverall water splitting10aoxygen evolution1 aIllathvalappil, Rajith1 aWalko, Priyanka, S.1 aKanheerampockil, Fayis1 aBhat, Suresh, K.1 aDevi, Nandini1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/hierarchical-nanoflower-arrays-co9s8-ni3s2-nickel-foam-highly-efficient-binder-free02525nas a2200289 4500008004100000245010200041210006900143260000900212300001400221490000600235520159000241653001701831653001401848653001401862653002101876653002101897653001901918653001501937653002701952100002201979700001902001700002302020700001802043700002202061700002002083856013202103 2024 eng d00aDurable and stable bifunctional Co3O4-based nanocatalyst for oxygen reduction/evolution reactions0 aDurable and stable bifunctional Co3O4based nanocatalyst for oxyg cFEB  a3620-36300 v73 a

The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are recognized as the core reaction processes in regenerative energy storage and conversion systems. The design of cost-effective and high-performance bifunctional ORR/OER electrocatalysts (ECs) is very important for their substantial commercialization. Herein, sponge-like Co3O4 nanoparticles anchored on carbon (Sp-Co3O4/C) are successfully fabricated by a facile two-step solvothermal strategy for ORR/OER in an alkaline electrolyte. The Sp-Co3O4/C EC exhibits promising bifunctional ORR/OER activity with ORR onset potential (E onset = 0.88 V vs RHE), half-wave potential (E (1/2) = 0.75 V), limiting current density (j = -6.60 mA cm(-2)), OER onset potential (E-onset = 1.26 V), and OER overpotential for 10% energy conversion (eta(10) = 0.38 V) in 0.1 M KOH. It demonstrates a significantly lower reversibility index (Delta E = E- j10 - E 1/2 = 0.86 V), comparable to standard Pt/C and RuO2 ECs. The superior ORR/OER performances of Sp-Co3O4/C EC can be ascribed to the synergistic contribution of a high electrochemically active surface area (48.33 m(2) g(-1)), BET surface area (131 m(2) g(-1)), the rich interfacial structure of the crystal facets (111), (220), and (311), and the abundant oxygen vacancies in the sponge-like morphology. Besides the methanol tolerance, accelerated durability and chronoamperometric test established excellent durability and stability in the electrocatalytic operation. This work offers insight into the development of high-performance ORR/OER ECs. [GRAPHICS]

10abifunctional10afuel cell10ainterface10aoxygen evolution10aoxygen reduction10aOxygen vacancy10aSp-Co3O4/C10asponge-like morphology1 aChutia, Bhugendra1 aChetry, Rashmi1 aRao, Komateedi, N.1 aSingh, Nittan1 aSudarsanam, Putla1 aBharali, Pankaj uhttps://library.ncl.res.in/content/durable-and-stable-bifunctional-co3o4-based-nanocatalyst-oxygen-reductionevolution-reactions