Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Water-splitting electrocatalysis in acid conditions using ruthenate-iridate pyrochlores.

ABSTRACT: The pyrochlore solid solution (Na(0.33)Ce(0.67))2(Ir(1-x)Ru(x))2O7 (0?x?1), containing B-site Ru(IV) and Ir(IV) is prepared by hydrothermal synthesis and used as a catalyst layer for electrochemical oxygen evolution from water at pH<7. The materials have atomically mixed Ru and Ir and their nanocrystalline form allows effective fabrication of electrode coatings with improved charge densities over a typical (Ru,Ir)O2 catalyst. An in?situ study of the catalyst layers using XANES spectroscopy at the Ir L(III) and Ru K?edges shows that both Ru and Ir participate in redox chemistry at oxygen evolution conditions and that Ru is more active than Ir, being oxidized by almost one oxidation state at maximum applied potential, with no evidence for ruthenate or iridate in +6 or higher oxidation states.

SUBMITTER: Sardar K

PROVIDER: S-EPMC4497602 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Water-splitting electrocatalysis in acid conditions using ruthenate-iridate pyrochlores.

Sardar Kripasindhu K Petrucco Enrico E Hiley Craig I CI Sharman Jonathan D B JD Wells Peter P PP Russell Andrea E AE Kashtiban Reza J RJ Sloan Jeremy J Walton Richard I RI

Angewandte Chemie (International ed. in English) 20140904 41

The pyrochlore solid solution (Na(0.33)Ce(0.67))2(Ir(1-x)Ru(x))2O7 (0≤x≤1), containing B-site Ru(IV) and Ir(IV) is prepared by hydrothermal synthesis and used as a catalyst layer for electrochemical oxygen evolution from water at pH<7. The materials have atomically mixed Ru and Ir and their nanocrystalline form allows effective fabrication of electrode coatings with improved charge densities over a typical (Ru,Ir)O2 catalyst. An in situ study of the catalyst layers using XANES spectroscopy at th ...[more]

PMID: 25196322

Similar Datasets

Spontaneous solar water splitting with decoupling of light absorption and electrocatalysis using silicon back-buried junction.

Project description:Converting sunlight into a storable form of energy by spontaneous water splitting is of great interest but the difficulty in simultaneous management of optical, electrical, and catalytic properties has limited the efficiency of photoelectrochemical (PEC) devices. Herein, we implemented a decoupling scheme of light harvesting and electrocatalysis by employing a back-buried junction (BBJ) PEC cell design, which enables >95% front side light-harvesting, whereas the electrochemical reaction in conjunction with carrier separation/transport/collection occurs on the back side of the PEC cell. The resultant silicon BBJ-PEC half-cell produces a current density of 40.51 mA cm-2 for hydrogen evolution by minimizing optical, electrical, and catalytic losses (as low as 6.11, 1.76, and 1.67 mA cm-2, respectively). Monolithic fabrication also enables three BBJ-PEC cells to be connected in series as a single module, enabling unassisted solar water-splitting with a solar-to-hydrogen conversion efficiency of 15.62% and a hydrogen generation rate of 240 μg cm-2 h-1.

| S-EPMC7411053 | biostudies-literature

Al2 Pt for Oxygen Evolution in Water Splitting: A Strategy for Creating Multifunctionality in Electrocatalysis.

Project description:The production of hydrogen via water electrolysis is feasible only if effective and stable catalysts for the oxygen evolution reaction (OER) are available. Intermetallic compounds with well-defined crystal and electronic structures as well as particular chemical bonding features are suggested here to act as precursors for new composite materials with attractive catalytic properties. Al2 Pt combines a characteristic inorganic crystal structure (anti-fluorite type) and a strongly polar chemical bonding with the advantage of elemental platinum in terms of stability against dissolution under OER conditions. We describe here the unforeseen performance of a surface nanocomposite architecture resulting from the self-organized transformation of the bulk intermetallic precursor Al2 Pt in OER.

| S-EPMC7539922 | biostudies-literature

Efficient overall water splitting in acid with anisotropic metal nanosheets.

Project description:Water is the only available fossil-free source of hydrogen. Splitting water electrochemically is among the most used techniques, however, it accounts for only 4% of global hydrogen production. One of the reasons is the high cost and low performance of catalysts promoting the oxygen evolution reaction (OER). Here, we report a highly efficient catalyst in acid, that is, solid-solution Ru‒Ir nanosized-coral (RuIr-NC) consisting of 3 nm-thick sheets with only 6 at.% Ir. Among OER catalysts, RuIr-NC shows the highest intrinsic activity and stability. A home-made overall water splitting cell using RuIr-NC as both electrodes can reach 10 mA cm-2geo at 1.485 V for 120 h without noticeable degradation, which outperforms known cells. Operando spectroscopy and atomic-resolution electron microscopy indicate that the high-performance results from the ability of the preferentially exposed {0001} facets to resist the formation of dissolvable metal oxides and to transform ephemeral Ru into a long-lived catalyst.

| S-EPMC7887272 | biostudies-literature

Strong Electronic Interaction Enhanced Electrocatalysis of Metal Sulfide Clusters Embedded Metal-Organic Framework Ultrathin Nanosheets toward Highly Efficient Overall Water Splitting.

Project description:Unique metal sulfide (MS) clusters embedded ultrathin nanosheets of Fe/Ni metal-organic framework (MOF) are grown on nickel foam (NiFe-MS/MOF@NF) as a highly efficient bifunctional electrocatalyst for overall water splitting. It exhibits remarkable catalytic activity and stability toward both the oxygen evolution reaction (OER, ? = 230 mV at 50 mA cm-2) and hydrogen evolution reaction (HER, ? = 156 mV at 50 mA cm-2) in alkaline media, and bi-functionally catalyzes overall alkaline water splitting at a current density of 50 mA cm-2 by 1.74 V cell voltage without iR compensation. The enhancement mechanism is ascribed to the impregnated metal sulfide clusters in the nanosheets, which not only promote the formation of ultrathin nanosheet to greatly enlarge the reaction surface area while offering high electric conductivity, but more importantly, efficiently modulate the electronic structure of the catalytically active atom sites to an electron-rich state via strong electronic interaction and strengthen the adsorption of oxygenate intermediate to facilitate fast electrochemical reactions. This work reports a highly efficient HER/OER bifunctional electrocatalyst and may shed light on the rational design and synthesis of uniquely structured MOF-derived catalysts.

| S-EPMC7578852 | biostudies-literature

Dynamic semiconductor-electrolyte interface for sustainable solar water splitting over 600 hours under neutral conditions.

Project description:Photoelectrochemical (PEC) water splitting that functions in pH-neutral electrolyte attracts increasing attention to energy demand sustainability. Here, we propose a strategy to in situ form a NiB layer by tuning the composition of the neutral electrolyte with the additions of nickel and borate species, which improves the PEC performance of the BiVO4 photoanode. The NiB/BiVO4 exhibits a photocurrent density of 6.0 mA cm-2 at 1.23 VRHE with an onset potential of 0.2 VRHE under 1 sun illumination. The photoanode displays a photostability of over 600 hours in a neutral electrolyte. The additive of Ni2+ in the electrolyte, which efficiently inhibits the dissolution of NiB, can accelerate the photogenerated charge transfer and enhance the water oxidation kinetics. The borate species with B─O bonds act as a promoter of catalyst activity by accelerating proton-coupled electron transfer. The synergy effect of both species suppresses the surface charge recombination and inhibits the photocorrosion of BiVO4.

| S-EPMC9812387 | biostudies-literature

Quadruple perovskite ruthenate as a highly efficient catalyst for acidic water oxidation.

Project description:Development of highly active and durable oxygen-evolving catalysts in acid media is a major challenge to design proton exchange membrane water electrolysis for producing hydrogen. Here, we report a quadruple perovskite oxide CaCu3Ru4O12 as a superior catalyst for acidic water oxidation. This complex oxide exhibits an ultrasmall overpotential of 171?mV at 10?mA?cm-2geo, which is much lower than that of the state-of-the-art RuO2. Moreover, compared to RuO2, CaCu3Ru4O12 shows a significant increase in mass activity by more than two orders of magnitude and much better stability. Density functional theory calculations reveal that the quadruple perovskite catalyst has a lower Ru 4d-band center relative to RuO2, which effectively optimizes the binding energy of oxygen intermediates and thereby enhances the catalytic activity.

| S-EPMC6707249 | biostudies-literature

Overall water splitting by Pt/g-C3N4 photocatalysts without using sacrificial agents.

Project description:We report the direct splitting of pure water by light-excited graphitic carbon nitride (g-C3N4) modified with Pt, PtO x , and CoO x as redox cocatalysts, while pure g-C3N4 is virtually inactive for overall water splitting by photocatalysis. The novelty is in the selective creation of both H2 and O2 cocatalysts on surface active sites of g-C3N4via photodeposition triggering the splitting of water for the simultaneous evolution of H2 and O2 gases in a stoichiometric ratio of 2?:?1, irradiated with light, without using any sacrificial reagents. The photocatalyst was stable for 510 hours of reaction.

| S-EPMC6005136 | biostudies-literature

Biphasic water splitting by osmocene.

Project description:The photochemical reactivity of osmocene in a biphasic water-organic solvent system has been investigated to probe its water splitting properties. The photoreduction of aqueous protons to hydrogen under anaerobic conditions induced by osmocene dissolved in 1,2-dichloroethane and the subsequent water splitting by the osmocenium metal-metal dimer formed during H(2) production were studied by electrochemical methods, UV-visible spectrometry, gas chromatography, and nuclear magnetic resonance spectroscopy. Density functional theory computations were used to validate the reaction pathways.

| S-EPMC3406862 | biostudies-other

Enhanced photoelectrochemical water splitting performance using morphology-controlled BiVO4 with W doping.

Project description:Nanostructures exhibit numerous merits to improve the efficiency in solar-to-energy conversion. These include shortened carrier collection pathways, an increased volume ratio between depletion layer and bulk, enhanced light capture due to multiple light scattering in nanostructures, and a high surface area for photochemical conversion reactions. In this study, we describe the synthesis of morphology-controlled W-doped BiVO4 by simply tuning the solvent ratio in precursor solutions. Planar and porous W-doped BiVO4 thin films were prepared and compared. The porous film, which exhibits increased surface area and enhanced light absorption, has displayed enhanced charge separation and interfacial charge injection. Our quantitative analysis showed an enhancement of about 50% of the photoelectrochemical performance for the porous structure compared to the planar structure. This enhancement is attributed to improved light absorption (13% increase), charge separation (14% increase), and interfacial charge injection (20% increase).

| S-EPMC5727771 | biostudies-other

Efficient electrolyzer for CO2 splitting in neutral water using earth-abundant materials.

Project description:Low-cost, efficient CO2-to-CO+O2 electrochemical splitting is a key step for liquid-fuel production for renewable energy storage and use of CO2 as a feedstock for chemicals. Heterogeneous catalysts for cathodic CO2-to-CO associated with an O2-evolving anodic reaction in high-energy-efficiency cells are not yet available. An iron porphyrin immobilized into a conductive Nafion/carbon powder layer is a stable cathode producing CO in pH neutral water with 90% faradaic efficiency. It is coupled with a water oxidation phosphate cobalt oxide anode in a home-made electrolyzer by means of a Nafion membrane. Current densities of approximately 1 mA/cm(2) over 30-h electrolysis are achieved at a 2.5-V cell voltage, splitting CO2 and H2O into CO and O2 with a 50% energy efficiency. Remarkably, CO2 reduction outweighs the concurrent water reduction. The setup does not prevent high-efficiency proton transport through the Nafion membrane separator: The ohmic drop loss is only 0.1 V and the pH remains stable. These results demonstrate the possibility to set up an efficient, low-voltage, electrochemical cell that converts CO2 into CO and O2 by associating a cathodic-supported molecular catalyst based on an abundant transition metal with a cheap, easy-to-prepare anodic catalyst oxidizing water into O2.

| S-EPMC4878489 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data