The Experts below are selected from a list of 27360 Experts worldwide ranked by ideXlab platform

Tomas Edvinsson - One of the best experts on this subject based on the ideXlab platform.

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    Journal of Physical Chemistry C, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon–free and sustainable fuel. Earth–abundant and non–precious metals are here of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt but the type of substrate could ultimately affect both the initial growth conditions as well as the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 at. % Ni, 70 at. % Mo) were sputtered on various substrates with different porosity and conductivity. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The elec...

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    The Journal of Physical Chemistry, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon-free and sustainable fuel. Earth-abundant and nonprecious metals are, here, of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt, but the type of the substrate could ultimately affect both the initial growth conditions and the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 atom % Ni, 70 atom % Mo) were sputtered on various substrates with different porosities and conductivities. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The electrochemical characterization was carried out with linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in the frequency range 0.7 Hz–100 kHz. LSV measurements were carried out at direct current (DC) potentials between 200 and −400 mV vs the reversible hydrogen electrode (RHE) in 1 M NaOH encompassing the HER. The lowest overpotentials for HER were obtained for films on the nickel foam at all current densities (−157 mV vs RHE @ 10 mA cm–²), and the overpotentials increased in the order of nickel foil, carbon cloth, fluorine-doped tin oxide, and indium tin oxide glass. EIS data were fitted with two equivalent circuit models and compared for different DC potentials and different substrate morphologies and conductivities. By critical evaluation of the data from the models, the influence of the substrates on the reaction kinetics was analyzed in the high- and low-frequency regions. In the high-frequency region, a strong substrate dependence was seen and interpreted with a Schottky-type barrier, which can be rationalized as being due to a potential barrier in the material heterojunctions or a resistive substrate–film oxide/hydroxide. The results highlight the importance of substrates, the total charge transfer properties in electrocatalysis, and the relevance of different circuit components in EIS and underpin the necessity to incorporate high-conductivity, chemically inert, and work-function-matched substrate–catalysts in the catalyst system.

Ilknur Bayrak Pehlivan - One of the best experts on this subject based on the ideXlab platform.

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    Journal of Physical Chemistry C, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon–free and sustainable fuel. Earth–abundant and non–precious metals are here of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt but the type of substrate could ultimately affect both the initial growth conditions as well as the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 at. % Ni, 70 at. % Mo) were sputtered on various substrates with different porosity and conductivity. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The elec...

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    The Journal of Physical Chemistry, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon-free and sustainable fuel. Earth-abundant and nonprecious metals are, here, of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt, but the type of the substrate could ultimately affect both the initial growth conditions and the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 atom % Ni, 70 atom % Mo) were sputtered on various substrates with different porosities and conductivities. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The electrochemical characterization was carried out with linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in the frequency range 0.7 Hz–100 kHz. LSV measurements were carried out at direct current (DC) potentials between 200 and −400 mV vs the reversible hydrogen electrode (RHE) in 1 M NaOH encompassing the HER. The lowest overpotentials for HER were obtained for films on the nickel foam at all current densities (−157 mV vs RHE @ 10 mA cm–²), and the overpotentials increased in the order of nickel foil, carbon cloth, fluorine-doped tin oxide, and indium tin oxide glass. EIS data were fitted with two equivalent circuit models and compared for different DC potentials and different substrate morphologies and conductivities. By critical evaluation of the data from the models, the influence of the substrates on the reaction kinetics was analyzed in the high- and low-frequency regions. In the high-frequency region, a strong substrate dependence was seen and interpreted with a Schottky-type barrier, which can be rationalized as being due to a potential barrier in the material heterojunctions or a resistive substrate–film oxide/hydroxide. The results highlight the importance of substrates, the total charge transfer properties in electrocatalysis, and the relevance of different circuit components in EIS and underpin the necessity to incorporate high-conductivity, chemically inert, and work-function-matched substrate–catalysts in the catalyst system.

Gunnar A Niklasson - One of the best experts on this subject based on the ideXlab platform.

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    Journal of Physical Chemistry C, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon–free and sustainable fuel. Earth–abundant and non–precious metals are here of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt but the type of substrate could ultimately affect both the initial growth conditions as well as the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 at. % Ni, 70 at. % Mo) were sputtered on various substrates with different porosity and conductivity. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The elec...

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    The Journal of Physical Chemistry, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon-free and sustainable fuel. Earth-abundant and nonprecious metals are, here, of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt, but the type of the substrate could ultimately affect both the initial growth conditions and the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 atom % Ni, 70 atom % Mo) were sputtered on various substrates with different porosities and conductivities. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The electrochemical characterization was carried out with linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in the frequency range 0.7 Hz–100 kHz. LSV measurements were carried out at direct current (DC) potentials between 200 and −400 mV vs the reversible hydrogen electrode (RHE) in 1 M NaOH encompassing the HER. The lowest overpotentials for HER were obtained for films on the nickel foam at all current densities (−157 mV vs RHE @ 10 mA cm–²), and the overpotentials increased in the order of nickel foil, carbon cloth, fluorine-doped tin oxide, and indium tin oxide glass. EIS data were fitted with two equivalent circuit models and compared for different DC potentials and different substrate morphologies and conductivities. By critical evaluation of the data from the models, the influence of the substrates on the reaction kinetics was analyzed in the high- and low-frequency regions. In the high-frequency region, a strong substrate dependence was seen and interpreted with a Schottky-type barrier, which can be rationalized as being due to a potential barrier in the material heterojunctions or a resistive substrate–film oxide/hydroxide. The results highlight the importance of substrates, the total charge transfer properties in electrocatalysis, and the relevance of different circuit components in EIS and underpin the necessity to incorporate high-conductivity, chemically inert, and work-function-matched substrate–catalysts in the catalyst system.

Miguel A Arvizu - One of the best experts on this subject based on the ideXlab platform.

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    Journal of Physical Chemistry C, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon–free and sustainable fuel. Earth–abundant and non–precious metals are here of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt but the type of substrate could ultimately affect both the initial growth conditions as well as the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 at. % Ni, 70 at. % Mo) were sputtered on various substrates with different porosity and conductivity. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The elec...

  • impedance spectroscopy modeling of nickel molybdenum Alloys on porous and flat substrates for applications in water splitting
    The Journal of Physical Chemistry, 2019
    Co-Authors: Ilknur Bayrak Pehlivan, Miguel A Arvizu, Gunnar A Niklasson, Tomas Edvinsson
    Abstract:

    Hydrogen production by splitting water using electrocatalysts powered by renewable energy from solar or wind plants is one promising alternative to produce a carbon-free and sustainable fuel. Earth-abundant and nonprecious metals are, here, of interest as a replacement for scarce and expensive platinum group catalysts. Ni–Mo is a promising alternative to Pt, but the type of the substrate could ultimately affect both the initial growth conditions and the final charge transfer in the system as a whole with resistive junctions formed in the heterojunction interface. In this study, we investigated the effect of different substrates on the hydrogen evolution reaction (HER) of Ni–Mo electrocatalysts. Ni–Mo catalysts (30 atom % Ni, 70 atom % Mo) were sputtered on various substrates with different porosities and conductivities. There was no apparent morphological difference at the surface of the catalytic films sputtered on the different substrates, and the substrates were classified from microporous to flat. The electrochemical characterization was carried out with linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) in the frequency range 0.7 Hz–100 kHz. LSV measurements were carried out at direct current (DC) potentials between 200 and −400 mV vs the reversible hydrogen electrode (RHE) in 1 M NaOH encompassing the HER. The lowest overpotentials for HER were obtained for films on the nickel foam at all current densities (−157 mV vs RHE @ 10 mA cm–²), and the overpotentials increased in the order of nickel foil, carbon cloth, fluorine-doped tin oxide, and indium tin oxide glass. EIS data were fitted with two equivalent circuit models and compared for different DC potentials and different substrate morphologies and conductivities. By critical evaluation of the data from the models, the influence of the substrates on the reaction kinetics was analyzed in the high- and low-frequency regions. In the high-frequency region, a strong substrate dependence was seen and interpreted with a Schottky-type barrier, which can be rationalized as being due to a potential barrier in the material heterojunctions or a resistive substrate–film oxide/hydroxide. The results highlight the importance of substrates, the total charge transfer properties in electrocatalysis, and the relevance of different circuit components in EIS and underpin the necessity to incorporate high-conductivity, chemically inert, and work-function-matched substrate–catalysts in the catalyst system.

J Crousier - One of the best experts on this subject based on the ideXlab platform.

  • influence of substrate on the electrodeposition of nickel molybdenum Alloys
    Journal of Applied Electrochemistry, 1992
    Co-Authors: J Crousier, Marielle Eyraud, J M Roman
    Abstract:

    The electrodeposition of Nickel-Molybdenum alloy has been studied on various substrates, with the aim of determining the influence of hydrogen evolution on the formation of the deposit. Transient electrochemical methods were used. Three types of substrates were used. Glassy carbon in which hydrogen absorption cannot occur, palladium in which hydrogen diffusion is rapid, and nickel. Good and thick deposits were obtained on glassy carbon and annealed ultra pure nickel. On palladium no deposit was formed. The importance of hydrogen in the formation of the deposit was confirmed. Codeposition occurs in the same potential range as hydrogen evolution, and therefore hydrogen is trapped in the expanding lattice as seen by its oxidation during anodic polarization.