A5072433173- Electrocatalysts for Energy Conversion
- Advanced Photocatalysis Techniques
- Electronic and Structural Properties of Oxides
- Electron and X-Ray Spectroscopy Techniques
- Semiconductor materials and devices
- Machine Learning in Materials Science
- CO2 Reduction Techniques and Catalysts
- Chalcogenide Semiconductor Thin Films
- Electrochemical Analysis and Applications
- Catalytic Processes in Materials Science
- Copper-based nanomaterials and applications
- Graphene research and applications
- Advanced battery technologies research
- Catalysis and Oxidation Reactions
- Ga2O3 and related materials
- Diamond and Carbon-based Materials Research
- Molecular Junctions and Nanostructures
- Carbon Nanotubes in Composites
- Semiconductor materials and interfaces
- Solar-Powered Water Purification Methods
- Solar Thermal and Photovoltaic Systems
- Scientific Computing and Data Management
- Surface and Thin Film Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Organic Electronics and Photovoltaics
California Institute of Technology
2015-2024
nLIGHT (United States)
2021-2023
Joint Center for Artificial Photosynthesis
2015-2021
University of California, Los Angeles
2021
Jet Propulsion Laboratory
2021
Division of Chemistry
2019-2020
Pasadena City College
2018-2020
Brandenburg University of Technology Cottbus-Senftenberg
2011-2019
Sensors (United States)
2019
Chemnitz University of Technology
2013
Efficient unassisted solar water splitting, a pathway to storable renewable energy in the form of chemical bonds, requires optimization photoelectrochemical device based on photovoltaic tandem heterojunctions. We report monolithic photocathode architecture that exhibits significantly reduced surface reflectivity, minimizing parasitic light absorption and reflection losses. A tailored multifunctional crystalline titania interphase layer acts as corrosion protection layer, with favorable band...
A biomimetic Z-scheme photocatalyst exhibits dramatically enhanced photocatalytic activity for H<sub>2</sub> production, driven by a tandem solid-state electron flow.
Solar-driven reduction of carbon dioxide represents a carbon-neutral pathway for the synthesis fuels and chemicals. We report here results solar-driven CO2 using gas diffusion electrode (GDE) directly powered by photovoltaic cell. A GaInP/GaInAs/Ge triple-junction cell was used to power reverse-assembled employing Ag nanoparticle catalyst layer. The device had solar-to-CO energy conversion efficiency 19.1% under simulated AM 1.5G illumination at 1 Sun. use GDE prevented transition from...
Via operando XPS, band bending, pinning, and other properties are observed.
Electrocatalysis of the oxygen evolution reaction is central to several energy technologies including electrolyzers, solar fuel generators, and air-breathing batteries. Strong acid electrolytes are desirable for many implementations these technologies, although deployment such device designs often hampered by lack non-precious-metal electrocatalysts, with Ir-based oxides comprising only known catalysts that exhibit stable activity at low overpotential. During our exploration Mn–Sb–O system...
Surface plasmon resonances in metal nanostructures enable the generation of nonequilibrium hot electron–hole pairs, which has received wide interest as a means to drive chemical reactions at nanoscale. However, harvesting holes plasmonic heterostructures oxidation balance photocatalytic CO2 reduction reaction been challenging. Further, details balanced redox pathways for gas-phase photocatalysis have difficult identify. Here, we report an Au/p-GaN heterostructure photocatalyst unassisted,...
Abstract Materials acceleration platforms (MAPs) operate on the paradigm of integrating combinatorial synthesis, high‐throughput characterization, automatic analysis, and machine learning. Within a MAP, one or multiple autonomous feedback loops may aim to optimize materials for certain functional properties generate new insights. The scope given experiment campaign is defined by range analysis actions that are integrated into framework. Herein, authors present method many within hierarchical...
Reduction of carbon dioxide in aqueous electrolytes at single-crystal MoS2 or thin-film electrodes yields 1-propanol as the major CO2 reduction product, along with hydrogen from water predominant process. Lower levels formate, ethylene glycol, and t-butanol were also produced. At an applied potential −0.59 V versus a reversible electrode, Faradaic efficiencies for to ∼3.5% single crystals ∼1% thin films low edge-site densities. is kinetically challenging reaction that requires overall...
Solid-state electrical, photoelectrochemical, and photoelectron spectroscopic techniques have been used to characterize the behavior electronic structure of interfaces between n-Si, n+-Si, or p+-Si surfaces amorphous coatings TiO2 formed using atomic-layer deposition. Photoelectrochemical measurements n-Si/TiO2/Ni in contact with a series one-electron, electrochemically reversible redox systems indicated that acted as buried junction whose photovoltage was independent formal potential...
Electrical transport in amorphous titanium dioxide (a-TiO2) thin films, deposited by atomic layer deposition (ALD), and across heterojunctions of p+-Si|a-TiO2|metal substrates that had various top metal contacts has been characterized ac conductivity, temperature-dependent dc space-charge-limited current spectroscopy, electron paramagnetic resonance (EPR) X-ray photoelectron density versus voltage (J–V) characteristics. Amorphous TiO2 films were fabricated using either...
Illuminated etched p-InP photocathode undergoes cathodic corrosion forming metallic In 0 , while electrodeposited Pt catalyst kinetically stabilizes the electrode surface against such a pathway.
Guided by computational Pourbaix screening and high-throughput experiments aimed at the development of precious-metal-free fuel cells, we investigate rutile CoSb2O6 as an electrocatalyst for oxygen reduction in 1 M sulfuric acid. Following 4 h catalyst conditioning 0.7 V vs RHE, operation this potential 20 yielded average current density −0.17 mA cm–2 with corrosion a rate 0.04 nm hour–1 that is stoichiometric composition. Surface analysis (111) surface identified partial H coverage under...
Human researchers multi-task, collaborate, and share resources. HELAO-async is a multi-workflow automation software that helps realize these attributes in materials acceleration platforms.
Photoelectrochemical CO2 reduction (CO2R) is an appealing solution for converting carbon dioxide into higher-value products. However, CO2R in aqueous electrolytes suffers from poor selectivity due to the competitive hydrogen evolution reaction that dominant on semiconductor surfaces electrolytes. We demonstrate functionalizing gold/p-type gallium nitride devices with a film derived diphenyliodonium triflate suppresses generation 90% 18%. As result, we observe increases Faradaic efficiency...
Long-term space missions require extra-terrestrial production of storable, renewable energy. Hydrogen is ascribed a crucial role for transportation, electrical power and oxygen generation. We demonstrate in series drop tower experiments that efficient direct hydrogen can be realized photoelectrochemically microgravity environment, providing an alternative route to existing life support technologies travel. The photoelectrochemical cell consists integrated catalyst-functionalized...
High loadings of Cu were integrated on the light-facing side Si microwire arrays used under simulated sunlight for photoelectrochemical reduction CO2(aq) to hydrocarbons in 0.10 M KHCO3(aq). Radial-junction n+p-Si decorated with exhibited absolute photocurrent densities comparable an uncovered surface. Moreover, respect a foil electrode, positive shift onset potential hydrocarbon formation at n+p-Si/Cu was equal or greater than photovoltage semiconductor alone. Selective electrodeposition...
The quest to identify materials with tailored properties is increasingly expanding into high-order composition spaces, a corresponding combinatorial explosion in the number of candidate materials. A key challenge discover regions space where have novel properties. Traditional predictive models for material are not accurate enough guide search. Herein, we use high-throughput measurements optical three-cation metal oxide spaces by identifying compositions whose trends cannot be explained...
Abstract Electrochemical water oxidation is an important anodic process necessary to support many cathodic fuel forming processes. Inexpensive materials capable of catalysis are render renewable energy technologies affordable. In this study, titanium diboride (TiB 2 ) microparticles were explored as oxygen‐evolution reaction (OER) electrocatalyst in 1.0 M HClO 4 . An overpotential 560±20 mV was required generate a current density 10 mA cm −2 with Faradaic efficiency >96 %. TiB exhibited...
The TiO2 films are prepared by atomic layer deposition (ALD) method using titanium isopropoxide precursors at 250 °C and analyzed resonant photoemission spectroscopy (resPES). We report on the Ti2p O1s core levels, valence band (VB) spectra x-ray absorption (XAS) data, photoelectron (resPES) profiles Ti3p edges. determine elemental abundance, position of VB maxima, partial density states (PDOS) in conduction (CB) collect these data a scheme. In addition, we analyze band-gap as well intrinsic...
The electrical and spectroscopic properties of the TiO2/Ni protection layer system, which enables stabilization otherwise corroding photoanodes, have been investigated in contact with electrolyte solutions by scanning-probe microscopy, electrochemistry in-situ ambient pressure X-ray photoelectron spectroscopy (AP-XPS). Specifically, energy-band relations p+-Si/ALD-TiO2/Ni interface determined for a selected range Ni thicknesses. AP-XPS measurements using tender X-rays were performed...