A5009748744- Electrocatalysts for Energy Conversion
- Advanced Photocatalysis Techniques
- CO2 Reduction Techniques and Catalysts
- Catalytic Processes in Materials Science
- Carbon Dioxide Capture Technologies
- Advanced battery technologies research
- Copper-based nanomaterials and applications
- Iron oxide chemistry and applications
- Electronic and Structural Properties of Oxides
- Random lasers and scattering media
- Electrochemical Analysis and Applications
- Ammonia Synthesis and Nitrogen Reduction
- Catalysts for Methane Reforming
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Carbon dioxide utilization in catalysis
- Transition Metal Oxide Nanomaterials
- TiO2 Photocatalysis and Solar Cells
- Fuel Cells and Related Materials
- Porphyrin and Phthalocyanine Chemistry
- Asymmetric Hydrogenation and Catalysis
- Atmospheric and Environmental Gas Dynamics
- Catalysis and Oxidation Reactions
- Hybrid Renewable Energy Systems
- Spectroscopy and Quantum Chemical Studies
Catalytic Innovations (United States)
2016-2022
Technion – Israel Institute of Technology
2019
Catalytic Materials (United States)
2018-2019
New England Center for Clinical Research
2019
Irvine Valley College
2018
Proton OnSite (United States)
2018
University of California, Irvine
2018
Broadcom (United States)
2017
Yale University
2012-2016
University of New Haven
2015
We report the highest external quantum efficiency measured on hematite (α-Fe(2)O(3)) without intentional doping in a water-splitting environment: 46% at λ = 400 nm. This result was enabled by introduction of TiSi(2) nanonets, which are highly conductive and have suitably high surface areas. The nanonets serve dual role as structural support an efficient charge collector, allowing for maximum photon-to-charge conversion. Without addition any oxygen-evolving catalysts, we obtained...
As the most commonly encountered form of iron oxide in nature, hematite is a semiconducting crystal with an almost ideal bandgap for solar water splitting. Compelled by this unique property and other advantages, including its abundance Earth's crust stability under harsh chemical conditions, researchers have studied several decades. In perspective, we provide concise overview challenges that prevented us from actualizing full potentials promising material. Particular attention paid to...
Heteronanostructured photoelectrodes were fabricated by atomic layer deposition of WO3 and stabilized with an Mn-based oxygen-evolving catalyst. The resulting electrode absorbs photons to create electrons holes, the separation which is assisted built-in field within semiconductor. Electrons are collected, holes transferred catalyst split H2O into oxygen hydrogen (see schematic). Detailed facts importance specialist readers published as "Supporting Information". Such documents peer-reviewed,...
Several application fields can benefit from solar-hydrogen technologies <italic>via</italic> specific short-term and long-term pathways.
Abstract Molecular catalysts are known for their high activity and tunability, but solubility limited stability often restrict use in practical applications. Here we describe how a molecular iridium catalyst water oxidation directly robustly binds to oxide surfaces without the need any external stimulus or additional linking groups. On conductive electrode surfaces, this heterogenized oxidizes with low overpotential, turnover frequency minimal degradation. Spectroscopic electrochemical...
A TiO(2)/TiSi(2) complex heteronanostructure was synthesized to improve the efficiencies of TiO(2) in photosplitting H(2)O. Photoactive served convert incident photons into separated charges, and supporting TiSi(2) nanonet acted as an efficient conductor transport charges. The structural complexity also provided a framework high surface area enhance photoabsorption. 16.7% peak conversion efficiency obtained when measured under monochromic UV illuminations. growth further explored extend...
We present evidence for Cp* being a sacrificial placeholder ligand in the [Cp*IrIII(chelate)X] series of homogeneous oxidation catalysts. UV–vis and 1H NMR profiles as well MALDI-MS data show rapid irreversible loss under reaction conditions, which likely proceeds through an intramolecular inner-sphere pathway reminiscent reductive situ elimination diolefin ligands hydrogenation catalysis by [(diene)MI(L,L′)]+ (M = Rh Ir) precursors. When oxidatively stable chelate are bound to iridium...
Molecular and heterogeneous water oxidation catalysts improve the performance of hematite as a photoanode <italic>via</italic> fundamentally different mechanisms.
Solar water splitting in acidic solutions has important technological implications, but not been demonstrated to date a dual absorber photoelectrochemical cell. The lack of functionally stable water-oxidation catalysts (WOCs) acids is key reason for this slow development. only WOCs that are at low pH Ir-based systems, which typically too expensive be implemented broadly. It now shown deficiency may corrected by applying an ultra-thin monolayer molecular Ir WOC hematite solar solutions....
We report the synthesis of core–shell–shell Au@SiO2@TiO2 nanostructures and demonstrate near-field plasmonic enhancement dye-sensitized solar cells (DSSCs) incorporating them. Isolated nanoparticles as well nanostructured aggregates with broadband light absorption throughout visible region are developed. Comparisons to theoretical calculations performed for provide further insight into their structure. show that efficiency enhancements greater than Au@SiO2 vary distance between molecular...
Organometallic iridium complexes bearing oxidatively stable chelate ligands are precursors for efficient homogeneous water-oxidation catalysts (WOCs), but their activity in oxygen evolution has so far been studied almost exclusively with sacrificial chemical oxidants. In this report, we study the electrochemical activation of Cp*Ir and demonstrate true electrode-driven water oxidation catalyzed by a species solution. Whereas Cp* exhibit no measurable O2-evolution activity, molecular formed...
We present the first analysis of performance hydroxamate linkers as compared to carboxylate and phosphonate groups when anchoring ruthenium-polypyridyl dyes TiO2 surfaces in dye-sensitized solar cells (DSSCs). The study provides fundamental insight into structure/function relationships that are critical for cell performance. Our DSSCs have been produced by using newly synthesized dye molecules characterized combining measurements simulations experimental current density–voltage (J-V)...
Efforts to improve the ease of assembly and robustness photoanodes for light-driven water oxidation have led development a modular method anchoring high-potential zinc porphyrins TiO2 via coordination surface-bound pyridine linkers. It is essential that groups provide strong electronic coupling between molecular dye metal oxide surface optimal electron injection they are robust under operating conditions system. Here, four linker molecules functionalized with either carboxylate, phosphonate,...
The solution structures of highly active Ir water-oxidation catalysts are elucidated by combining density functional theory, high-energy X-ray scattering (HEXS), and extended absorption fine structure (EXAFS) spectroscopy. We find that the dimers with mono-μ-O cores terminal anionic ligands, generated in situ through partial oxidation a common catalyst precursor. proposed supported 1H 17O NMR, EPR, resonance Raman UV–vis spectra, electrophoresis, etc. Our findings particularly valuable to...
Heteronanostrukturierte Photoelektroden wurden durch Abscheidung von WO3-Schichten hergestellt und mit einem O2-entwickelnden Mangan-Katalysator stabilisiert. So präparierte Elektroden absorbieren Photonen unter Bildung Elektronen Löchern, deren Trennung das elektrische Feld des Halbleiters unterstützt wird. werden gesammelt Löcher zum Katalysator transferiert, um H2O in Sauerstoff Wasserstoff zu spalten (siehe Bild). Detailed facts of importance to specialist readers are published as...
The ability of PPors to photo-oxidize Ir(III)Cp* Ir(IV)Cp* indicates that they are promising photoanode components.
A fundamental issue that limits the efficiency of many photoelectrochemical systems is photon absorption length typically much longer than electron diffusion length. Various management schemes have been developed to enhance light absorption; one simple approach use randomly scattering media enable broadband and wide-angle enhancement. However, such are often opaque, making it difficult probe photo-induced processes. Here we wave interference effects modify spatial distribution inside a...
Time-resolved terahertz (THz) spectroscopy and open-circuit photovoltage measurements were employed to examine the size-dependent charge carrier dynamics of tungsten(VI) oxide (WO3) particles for their use as photoanode in photoelectrochemical cells. Specifically, films commercially available WO3 nanoparticles (NPs) granular (GPs) with diameters 77 ± 34 390 260 nm, respectively, examined air while immersed 0.1 M Na2SO4 electrolyte (pH = 2). Examination frequency-dependent transient...
This paper introduces IrI(CO)2(pyalc) (pyalc = (2-pyridyl)-2-propanoate) as an atom-efficient precursor for Ir-based homogeneous oxidation catalysis. compound was chosen to simplify analysis of the water catalyst species formed by previously reported Cp*IrIII(pyalc)OH precatalyst. Here, we present a comparative study on chemical and catalytic properties these two precursors. Previous studies show that oxidative activation Cp*Ir-based precursors with NaIO4 results in formation blue IrIV...