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Fang Song - One of the best experts on this subject based on the ideXlab platform.
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a nickel iron diselenide derived efficient Oxygen Evolution catalyst
Nature Communications, 2016Co-Authors: Fang SongAbstract:Efficient Oxygen-Evolution reaction catalysts are required for the cost-effective generation of solar fuels. Metal selenides have been reported as promising Oxygen-Evolution catalysts; however, their active forms are yet to be elucidated. Here we show that a representative selenide catalyst, nickel selenide, is entirely converted into nickel hydroxide under Oxygen-Evolution conditions. This result indicates that metal selenides are unstable during Oxygen Evolution, and the in situ generated metal oxides are responsible for their activity. This knowledge inspired us to synthesize nanostructured nickel iron diselenide, a hitherto unknown metal selenide, and to use it as a templating precursor to a highly active nickel iron oxide catalyst. This selenide-derived oxide catalyses Oxygen Evolution with an overpotential of only 195 mV for 10 mA cm(-2). Our work underscores the importance of identifying the active species of Oxygen-Evolution catalysts, and demonstrates how such knowledge can be applied to develop better catalysts.
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ni2p as a janus catalyst for water splitting the Oxygen Evolution activity of ni2p nanoparticles
Energy and Environmental Science, 2015Co-Authors: Lucasalexandre Stern, Ligang Feng, Fang SongAbstract:Electrochemical water splitting into hydrogen and Oxygen is a promising method for solar energy storage. The development of efficient electrocatalysts for water splitting has drawn much attention. However, catalysts that are active for both the hydrogen Evolution and Oxygen Evolution reactions are rare. Herein, we show for the first time that nickel phosphide (Ni2P), an excellent hydrogen evolving catalyst, is also highly active for Oxygen Evolution. A current density of 10 mA cm−2 is generated at an overpotential of only 290 mV in 1 M KOH. The high activity is attributed to the core–shell (Ni2P/NiOx) structure that the material adopts under catalytic conditions. The Ni2P nanoparticles can serve as both cathode and anode catalysts for an alkaline electrolyzer, which generates 10 mA cm−2 at 1.63 V.
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ultrathin cobalt manganese layered double hydroxide is an efficient Oxygen Evolution catalyst
Journal of the American Chemical Society, 2014Co-Authors: Fang Song, Xile HuAbstract:Cost-effective production of solar fuels requires robust and earth-abundant Oxygen Evolution reaction (OER) catalysts. Herein, we report that ultrathin nanoplates of cobalt–manganese layered double hydroxide (CoMn LDH) are a highly active and stable Oxygen Evolution catalyst. The catalyst was fabricated by a one-pot coprecipitation method at room temperature, and its turnover frequency (TOF) is more than 20 times higher than the TOFs of Co and Mn oxides and hydroxides, and 9 times higher than the TOF of a precious IrO2 catalyst. The activity of the catalyst was promoted by anodic conditioning, which was proposed to form amorphous regions and reactive Co(IV) species on the surface. The stability of the catalyst was demonstrated by continued electrolysis.
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exfoliation of layered double hydroxides for enhanced Oxygen Evolution catalysis
Nature Communications, 2014Co-Authors: Fang SongAbstract:The Oxygen Evolution reaction is a key reaction in water splitting. The common approach in the development of Oxygen Evolution catalysts is to search for catalytic materials with new and optimized chemical compositions and structures. Here we report an orthogonal approach to improve the activity of catalysts without alternating their compositions or structures. Specifically, liquid phase exfoliation is applied to enhance the Oxygen Evolution activity of layered double hydroxides. The exfoliated single-layer nanosheets exhibit significantly higher Oxygen Evolution activity than the corresponding bulk layered double hydroxides in alkaline conditions. The nanosheets from nickel iron and nickel cobalt layered double hydroxides outperform a commercial iridium dioxide catalyst in both activity and stability. The exfoliation creates more active sites and improves the electronic conductivity. This work demonstrates the promising catalytic activity of single-layered double hydroxides for the Oxygen Evolution reaction.
Shannon W Boettcher - One of the best experts on this subject based on the ideXlab platform.
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solution cast metal oxide thin film electrocatalysts for Oxygen Evolution
Journal of the American Chemical Society, 2012Co-Authors: Lena Trotochaud, James K Ranney, Kerisha N Williams, Shannon W BoettcherAbstract:Water oxidation is a critical step in water splitting to make hydrogen fuel. We report the solution synthesis, structural/compositional characterization, and Oxygen Evolution reaction (OER) electrocatalytic properties of ∼2–3 nm thick films of NiOx, CoOx, NiyCo1–yOx, Ni0.9Fe0.1Ox, IrOx, MnOx, and FeOx. The thin-film geometry enables the use of quartz crystal microgravimetry, voltammetry, and steady-state Tafel measurements to study the electrocatalytic activity and electrochemical properties of the oxides. Ni0.9Fe0.1Ox was found to be the most active water oxidation catalyst in basic media, passing 10 mA cm–2 at an overpotential of 336 mV with a Tafel slope of 30 mV dec–1 with Oxygen Evolution reaction (OER) activity roughly an order of magnitude higher than IrOx control films and similar to the best known OER catalysts in basic media. The high activity is attributed to the in situ formation of layered Ni0.9Fe0.1OOH oxyhydroxide species with nearly every Ni atom electrochemically active. In contrast to pr...
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solution cast metal oxide thin film electrocatalysts for Oxygen Evolution
Journal of the American Chemical Society, 2012Co-Authors: Lena Trotochaud, James K Ranney, Kerisha N Williams, Shannon W BoettcherAbstract:Water oxidation is a critical step in water splitting to make hydrogen fuel. We report the solution synthesis, structural/compositional characterization, and Oxygen Evolution reaction (OER) electrocatalytic properties of ∼2–3 nm thick films of NiOx, CoOx, NiyCo1–yOx, Ni0.9Fe0.1Ox, IrOx, MnOx, and FeOx. The thin-film geometry enables the use of quartz crystal microgravimetry, voltammetry, and steady-state Tafel measurements to study the electrocatalytic activity and electrochemical properties of the oxides. Ni0.9Fe0.1Ox was found to be the most active water oxidation catalyst in basic media, passing 10 mA cm–2 at an overpotential of 336 mV with a Tafel slope of 30 mV dec–1 with Oxygen Evolution reaction (OER) activity roughly an order of magnitude higher than IrOx control films and similar to the best known OER catalysts in basic media. The high activity is attributed to the in situ formation of layered Ni0.9Fe0.1OOH oxyhydroxide species with nearly every Ni atom electrochemically active. In contrast to pr...
S Rondinini - One of the best experts on this subject based on the ideXlab platform.
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screening of Oxygen Evolution electrocatalysts by scanning electrochemical microscopy using a shielded tip approach
Analytical Chemistry, 2008Co-Authors: A Minguzzi, Mario A Alpucheaviles, Joaquin Rodriguez Lopez, S Rondinini, Allen J BardAbstract:Oxygen Evolution electrocatalysts in acidic media were studied by scanning electrochemical microscopy (SECM) in the substrate generation−tip collection (SG−TC) imaging mode with a 100 µm diam tip. Pure IrO2 and Sn1−xIrxO2 combinatorial mixtures were prepared by a sol−gel route to form arrays of electrocatalyst spots. The experimental setup has been developed to optimize screening of electrocatalyst libraries under conditions where the entire array is capable of the Oxygen Evolution reaction (OER). The activity of individual spots was determined by reducing the interference from the reaction products of neighboring spots diffusing to the tip over the spot of interest. A gold layer deposited on the external wall of the SECM tip was used as a tip shield. In this study the shield was kept at a constant potential to reduce Oxygen under mass transfer controlled conditions. The tip shield consumes Oxygen coming from the neighbor spots in the array and enables the tip to correctly detect the activity of the spot ...
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Screening of Oxygen Evolution electrocatalysts by scanning electrochemical microscopy using a shielded tip approach.
Analytical chemistry, 2008Co-Authors: A Minguzzi, Mario A. Alpuche-aviles, Joaquin Rodriguez Lopez, S RondininiAbstract:Oxygen Evolution electrocatalysts in acidic media were studied by scanning electrochemical microscopy (SECM) in the substrate generation−tip collection (SG−TC) imaging mode with a 100 µm diam tip. ...
A Minguzzi - One of the best experts on this subject based on the ideXlab platform.
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screening of Oxygen Evolution electrocatalysts by scanning electrochemical microscopy using a shielded tip approach
Analytical Chemistry, 2008Co-Authors: A Minguzzi, Mario A Alpucheaviles, Joaquin Rodriguez Lopez, S Rondinini, Allen J BardAbstract:Oxygen Evolution electrocatalysts in acidic media were studied by scanning electrochemical microscopy (SECM) in the substrate generation−tip collection (SG−TC) imaging mode with a 100 µm diam tip. Pure IrO2 and Sn1−xIrxO2 combinatorial mixtures were prepared by a sol−gel route to form arrays of electrocatalyst spots. The experimental setup has been developed to optimize screening of electrocatalyst libraries under conditions where the entire array is capable of the Oxygen Evolution reaction (OER). The activity of individual spots was determined by reducing the interference from the reaction products of neighboring spots diffusing to the tip over the spot of interest. A gold layer deposited on the external wall of the SECM tip was used as a tip shield. In this study the shield was kept at a constant potential to reduce Oxygen under mass transfer controlled conditions. The tip shield consumes Oxygen coming from the neighbor spots in the array and enables the tip to correctly detect the activity of the spot ...
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Screening of Oxygen Evolution electrocatalysts by scanning electrochemical microscopy using a shielded tip approach.
Analytical chemistry, 2008Co-Authors: A Minguzzi, Mario A. Alpuche-aviles, Joaquin Rodriguez Lopez, S RondininiAbstract:Oxygen Evolution electrocatalysts in acidic media were studied by scanning electrochemical microscopy (SECM) in the substrate generation−tip collection (SG−TC) imaging mode with a 100 µm diam tip. ...
Lena Trotochaud - One of the best experts on this subject based on the ideXlab platform.
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solution cast metal oxide thin film electrocatalysts for Oxygen Evolution
Journal of the American Chemical Society, 2012Co-Authors: Lena Trotochaud, James K Ranney, Kerisha N Williams, Shannon W BoettcherAbstract:Water oxidation is a critical step in water splitting to make hydrogen fuel. We report the solution synthesis, structural/compositional characterization, and Oxygen Evolution reaction (OER) electrocatalytic properties of ∼2–3 nm thick films of NiOx, CoOx, NiyCo1–yOx, Ni0.9Fe0.1Ox, IrOx, MnOx, and FeOx. The thin-film geometry enables the use of quartz crystal microgravimetry, voltammetry, and steady-state Tafel measurements to study the electrocatalytic activity and electrochemical properties of the oxides. Ni0.9Fe0.1Ox was found to be the most active water oxidation catalyst in basic media, passing 10 mA cm–2 at an overpotential of 336 mV with a Tafel slope of 30 mV dec–1 with Oxygen Evolution reaction (OER) activity roughly an order of magnitude higher than IrOx control films and similar to the best known OER catalysts in basic media. The high activity is attributed to the in situ formation of layered Ni0.9Fe0.1OOH oxyhydroxide species with nearly every Ni atom electrochemically active. In contrast to pr...
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solution cast metal oxide thin film electrocatalysts for Oxygen Evolution
Journal of the American Chemical Society, 2012Co-Authors: Lena Trotochaud, James K Ranney, Kerisha N Williams, Shannon W BoettcherAbstract:Water oxidation is a critical step in water splitting to make hydrogen fuel. We report the solution synthesis, structural/compositional characterization, and Oxygen Evolution reaction (OER) electrocatalytic properties of ∼2–3 nm thick films of NiOx, CoOx, NiyCo1–yOx, Ni0.9Fe0.1Ox, IrOx, MnOx, and FeOx. The thin-film geometry enables the use of quartz crystal microgravimetry, voltammetry, and steady-state Tafel measurements to study the electrocatalytic activity and electrochemical properties of the oxides. Ni0.9Fe0.1Ox was found to be the most active water oxidation catalyst in basic media, passing 10 mA cm–2 at an overpotential of 336 mV with a Tafel slope of 30 mV dec–1 with Oxygen Evolution reaction (OER) activity roughly an order of magnitude higher than IrOx control films and similar to the best known OER catalysts in basic media. The high activity is attributed to the in situ formation of layered Ni0.9Fe0.1OOH oxyhydroxide species with nearly every Ni atom electrochemically active. In contrast to pr...
