A5040294814- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Chemical Looping and Thermochemical Processes
- Catalytic Processes in Materials Science
- Magnetic and transport properties of perovskites and related materials
- Copper-based nanomaterials and applications
- Advanced Photocatalysis Techniques
- Electronic and Structural Properties of Oxides
- High Entropy Alloys Studies
- High-Temperature Coating Behaviors
- Catalysis and Oxidation Reactions
- CO2 Reduction Techniques and Catalysts
- Advancements in Solid Oxide Fuel Cells
- Electrocatalysts for Energy Conversion
- Multiferroics and related materials
- Adsorption and Cooling Systems
- Advanced Condensed Matter Physics
- Carbon dioxide utilization in catalysis
- Ionic liquids properties and applications
- Nuclear Materials and Properties
- Advanced materials and composites
- Magnetic properties of thin films
- Thermal and Kinetic Analysis
- Chalcogenide Semiconductor Thin Films
- Electrostatics and Colloid Interactions
Sandia National Laboratories
2020-2024
Princeton University
2015-2019
Princeton Public Schools
2019
The chemical complexity of single-phase multicationic oxides, commonly termed high entropy oxides (HEOs), enables the integration conventionally incompatible metal cations into a single-crystalline phase. However, few studies have effectively leveraged nature HEOs for optimization disparate physical and properties. Here, we apply HEO concept to design robust oxidation catalysts in which oxide composition is tailored simultaneously achieve catalytic activity, oxygen storage capacity, thermal...
Solar thermochemical hydrogen (STCH) production is a promising method to generate carbon neutral fuels by splitting water utilizing metal oxide materials and concentrated solar energy. The discovery of with enhanced water-splitting performance critical for STCH play major role in the emerging renewable energy portfolio. While perovskite have been focus many recent efforts, screening can be time consuming due myriad chemical compositions possible. This greatly accelerated through...
Material design is increasingly used to realize desired functional properties, and the perovskite structure family one of richest most diverse: perovskites are employed in many applications due their structural flexibility compositional diversity. Hexagonal, layered structures with chains face-sharing transition metal oxide octahedra have attracted great interest as quantum materials magnetic electronic properties. Ba
In the search for improved materials photoelectrochemical water splitting, it has become important to identify new classes of semiconductor that may serve as photocathodes. To this end, p-type AgRhO2 been synthesized and tested a photocathode splitting. The is found exhibit excellent photocatalytic capability reducing protons H2 across wide range pH values with nearly 100% faradaic efficiency good photostability. Polycrystalline electrodes strong preferred c-axis orientation, resulting in...
[Mn(bpy)(CO)3Br] is recognized as a benchmark electrocatalyst for CO2 reduction to CO, with the doubly reduced [Mn(bpy)(CO)3]- proposed be active species in catalytic mechanism. The reaction of this intermediate and two protons expected produce tetracarbonyl cation, [Mn(bpy)(CO)4]+, thereby closing cycle. However, has not been experimentally observed. In study, [Mn(bpy)(CO)4][SbF6] (1) was directly synthesized found an efficient CO presence H2O. Complex 1 characterized using X-ray...
The resurgence of interest in a hydrogen economy and the development hydrogen-related technologies has initiated numerous research efforts aimed at making generation, storage, transportation more efficient affordable. Solar thermochemical production (STCH) is process that potentially exhibits benefits such as high reaction efficiencies, tunable thermodynamics, continued performance over extended cycling. Although CeO2 been de facto standard STCH material for many years, recently...
Despite significant recent developments in the field of high entropy oxides, previously reported HEOs are overwhelmingly stoichiometric structures containing a single cationic site and stabilized solely by intermixing increasing numbers cations. For first time, we demonstrate here that vacancies can significantly increase configurational stabilize phase-pure HEOs. Aluminate spinel with AB2O4 stoichiometry used as model crystal structure. These spinels tolerate large divalent cation...
BaCe0.25Mn0.75O3−δ (BCM), a non-stoichiometric oxide with layered perovskite-like crystal structure, has recently emerged as prospective contender for application in renewable energy harvesting by solar thermochemical hydrogen generation. Using solar–thermal and reducing environment, oxygen vacancies can be created high-temperature BCM, the reduced so obtained can, turn, produce H2 stripping from H2O. Therefore, first step toward understanding working mechanism optimizing performance of BCM...
In a search for improved photocathode materials fuel-producing photoelectrochemical cells, quaternary AgxCu1–xGayIn1–yS2 (0 ≤ x 1.0, 0 y 1.0) p-type, chalcopyrite semiconductors (SCIGS) were prepared and tested photochemical hydrogen evolution. The study reported here is based on the preparation of bulk phases system. contrast to thin-film studies this system, approach enables enhanced control materials' chemical, structural, electronic properties. Compared ternary CIGS electrode materials,...
To synthetically target a specific material with select performance, the underlying relationship between structure and function must be understood. For targeting magnetic properties, such understanding is underdeveloped for relatively new class of layered hexagonal perovskites, 12R-Ba4MMn3O12 family. Here, we perform detailed magnetostructural study perovskite materials 12R-Ba4MMn3O12, where M = diamagnetic Ce4+ or paramagnetic Jeff ≈ 1/2 Pr4+. The an antiferromagnet below TN 7.75 K, while...
The resurgence of interest in hydrogen-related technologies has stimulated new studies aimed at advancing lesser-developed water-splitting processes, such as solar thermochemical hydrogen production (STCH). Progress STCH been largely hindered by a lack materials able to efficiently split water rate comparable ceria under identical experimental conditions. BaCe 0.25 Mn 0.75 O 3 (BCM) recently demonstrated enhanced over and the potential further our understanding two-step cycles. A significant...
Solar thermochemical hydrogen production (STCH) via redox-active metal oxides is an approach for direct solar-driven generation typically using a high-temperature redox cycle involving refractory and steam. Typical cycles involve reduction of to form oxygen vacancies, followed by lower temperature reaction between vacancies steam where the oxide re-oxidized reduced hydrogen. Only few materials have demonstrated reversible cycling under harsh STCH conditions ( e.g. 1500°C reduction, 900°C...
BaCe$_{0.25}$Mn$_{0.75}$O$_{3-δ}$ (BCM), a non-stoichiometric oxide closely resembling perovskite crystal structure, has recently emerged as prospective contender for application in renewable energy harvesting by solar thermochemical hydrogen generation. Using energy, oxygen-vacancies can be created BCM and the reduced so obtained can, turn, produce H2 stripping oxygen from H2O. Therefore, first step toward understanding working mechanism optimizing performance of BCM, is thorough...