A5064240514- Iron oxide chemistry and applications
- Metal-Organic Frameworks: Synthesis and Applications
- Radioactive element chemistry and processing
- Electron and X-Ray Spectroscopy Techniques
- CO2 Sequestration and Geologic Interactions
- Hydrocarbon exploration and reservoir analysis
- Advanced Thermoelectric Materials and Devices
- X-ray Spectroscopy and Fluorescence Analysis
- Geological and Geochemical Analysis
- Semiconductor materials and devices
- Advancements in Battery Materials
- Enhanced Oil Recovery Techniques
- Chemical Synthesis and Characterization
- Covalent Organic Framework Applications
- Electronic and Structural Properties of Oxides
- Supramolecular Chemistry and Complexes
- Nuclear Materials and Properties
- Synthesis and Catalytic Reactions
- Graphene research and applications
- Minerals Flotation and Separation Techniques
- Gas Sensing Nanomaterials and Sensors
- Thermal properties of materials
- Calcium Carbonate Crystallization and Inhibition
- Molecular Sensors and Ion Detection
- Supramolecular Self-Assembly in Materials
Pacific Northwest National Laboratory
2020-2025
Battelle
2022-2023
SimulConsult
2021
Oregon State Library
2021
University of North Texas
2021
University of Utah
2016-2020
Environmental Molecular Sciences Laboratory
2020
Indian Institute of Technology Madras
2015
A family of 2D coordination polymers were successfully synthesized through "bottom-up" techniques using Ni2+, Cu2+, Co2+, and hexaaminobenzene. Liquid–liquid air–liquid interfacial reactions used to realize thick (∼1–2 μm) thin (<10 nm) stacked layers nanosheet, respectively. Atomic-force microscopy scanning electron both revealed the smooth flat nature nanosheets. Selected area diffraction was elucidate hexagonal crystal structure framework. Electronic devices fabricated on samples Ni...
The Al K alpha, 1486.6 eV, based x-ray photoelectron spectroscopy (XPS) of Fe 2p and 3p for Fe(III) in Fe2O3 Fe(II) FeO is compared with theoretical predictions on ab initio wavefunctions that accurately treat the final, core-hole, multiplets. principal objectives this comparison are to understand multiplet structure evaluate use both spectra determining oxidation states. In order properly interpret features these XPS provide atomistic insights as well atomic composition, it necessary origin...
The origin and assignment of the complex main satellite X-ray photoelectron spectroscopy (XPS) features cations in ionic compounds have been subject extensive theoretical studies using different methods. There is agreement that within a molecular orbital model, one needs to take into account types configurations. Specifically, those where core electron removed, but no other configuration changes are made addition ionization, there also shake or charge-transfer configuration. However, strong...
Curcumin (Cur) is a naturally occurring anticancer drug isolated from the Curcuma longa plant. It known to exhibit properties via inhibiting STAT3 phosphorylation process. However, its poor water solubility and low bioavailability impede clinical application. Herein, we used organoplatinum(II) ← pyridyl coordination-driven self-assembly cucurbit[8]uril (CB[8])-mediated heteroternary host-guest complex formation in concert produce an effective delivery system that transports Cur into cancer...
The origins of the complex Fe 2p X-Ray Photoelectron Spectra (XPS) hematite (α-Fe2O3) are analyzed and related to character bonding in this compound. This analysis provides a new novel view reasons for XPS binding energies (BEs) BE shifts, which deepens current understanding interpretation physical chemical significance XPS. In particular, many-body effects considered initial final, 2p-hole configuration wavefunctions. It is shown that one-body or one-configuration not sufficient many-body,...
Although the origin and assignment of complex XPS features cations in ionic compounds has been subject extensive theoretical work, agreement with experimental observations remains insufficient for unambiguous interpretation. This paper presents a rigorous ab initio treatment main satellite Fe 2p Fe2O3. possible using unique methodology selection orbitals that are used to form wavefunctions. orbital makes it treat both angular momentum coupling open shell core valence electrons as well shake...
Surface terminations and defects play a central role in determining how water interacts with metal oxides, thereby setting important properties of the interface that govern reactivity such as type distribution hydroxyl groups. However, interconnections between facets remain poorly understood. This limits usefulness conventional notions hydroxylation is controlled by cation exposure at surface. Here, using hematite (α-Fe2O3) model system, we show oxygen vacancies overwhelm surface...
Solar photoexcitation of chromophoric groups in dissolved organic matter (DOM), when coupled to photoreduction ubiquitous Fe(III)-oxide nanoparticles, can significantly accelerate DOM degradation near-surface terrestrial systems, but the mechanisms these reactions remain elusive. We examined photolysis soil coated onto hematite nanoplatelets featuring (001) exposed facets using a combination molecular spectroscopies and density functional theory (DFT) computations. Reactive oxygen species...
Mitigating the deleterious effects of climate change requires development and implementation carbon capture storage technologies. To expand monitoring, verification, reporting (MRV) capabilities geologic mineralization projects, we developed a thermogravimetric analysis–mass spectrometry (TGA–MS) methodology to enable quantification <100 ppm calcite (CaCO3) in complex samples. We extended TGA–MS calibration curves higher measurement resolution lower limits for evolved CO2 from...
Locating and developing ideal sites for large-scale capture storage of carbon dioxide has become increasingly necessary due to increasing global emissions warming. Mafic–ultramafic rocks present a unique geologic setting as they can trap injected CO2 in pore space, mineralize that permanently store it carbonate minerals, simultaneously release critical minerals. However, these reservoirs are undercharacterized relative sedimentary settings. In this study, we execute methodology determining...
Abstract Two‐dimensional coordination polymers (2DCPs) have been predicted to exhibit exotic properties such as superconductivity, topological insulating behavior, catalytic activity, and superior ion transport for energy applications; experimentally, these materials fallen short of their expectation due the lack synthesis protocols that yield continuous, large crystallite domains, highly ordered thin films with controllable physical chemical properties. Herein, fabrication large‐area, 2DCP...
The covalent character of the interaction between metal cation and oxygen ligands has been examined for two Fe oxides with different nominal oxidation states, Fe(II)O, Fe(III)2O3. is initial, ground state configuration ionic states involving removal a shallow core, 3p, deep 2p, electron. covalency assessed based on novel theoretical analyses wave functions various cases. It found that considerably ionized non-ionized configurations. changes in ions are shown to be responsible important...
Carbon-negative strategies such as geologic carbon sequestration in continental flood basalts offers a promising route to the removal of greenhouse gases, CO2, via safe and permanent storage stable carbonates. This potential has been successfully demonstrated at field scale Wallula Basalt Carbon Storage Pilot Project where supercritical CO2 was injected into Columbia River Group (CRBG). Here, we analyze recovered post-injection sidewall core cross-sections containing carbonate nodules using...
Nanoscale iron oxides (e.g., hematite (α-Fe2O3)) have unique properties, such as enhanced chemical reactivity and high surface area, when compared with their bulk counterparts. These nanoscale surfaces can be more reactive due to the presence of defects oxygen vacancies). In this work, we probed chemistry via X-ray photoelectron spectroscopy, electron microscopy, powder diffraction. Oxygen exposure vacuum annealing experiments were conducted add or remove vacancies adventitious carbon....
Successful deployment of in situ subsurface remediation strategies requires knowledge contaminant geochemistry, and the impact physicochemical sediment properties on remedy performance. Bismuth (Bi) materials can sequester multiple contaminants...
CO2-Enhanced Mineral Recovery (CO2-EMR) is a deep in situ mining technology that utilizes an engineered CO2 leaching fluid to extract nickel (Ni) and cobalt (Co) from subsurface ultramafic rocks, while simultaneously permanently mineralizing as carbonate minerals. This carbon negative process can contribute meeting the mineral demands of current emerging energy technologies. We calculate amount Ni Co available for recovery, mineralized via this generic intrusion 14 intrusions globally. If 5%...
Electrically conductive two‐dimensional (2D) metal–organic frameworks (MOFs) have emerged as good candidates for thermoelectric applications due to their high electrical and low thermal conductivities. This work studies the microscopic origin of properties copper benzenehexathiol (Cu‐BHT), a highly electrically 2D MOF. MOFs usually polycrystalline domains because bottom‐up synthesis, polycrystallinity makes it challenging understand intrinsic MOFs. Mesoscopic‐scale devices are fabricated...
This paper describes the development and provides comparisons of thiolated (−SH) unthiolated Ag–Al–Si–O xerogels for iodine gas capture. These were produced from alkoxides then heat-treated at 350 °C to provide mechanical strength subsequent processing steps. Then, a portion was using (3-mercaptopropyl)trimethoxysilane. Next, batches ion-exchanged in AgNO3 solutions where Ag+ replaced Na+ gel network on near 1:1 molar basis. Subsamples Ag-exchanged subjected reduction step H2/Ar convert Ag0...
Nanoparticle aggregates in solution controls surface reactivity and function. Complete dispersion often requires additive sorbents to impart a net repulsive interaction between particles. Facet engineering of nanocrystals offers an alternative approach produce monodisperse suspensions simply based on facet-specific with solvent molecules. Here, we measure the dispersion/aggregation three morphologies hematite (α-Fe
Abstract Geologic carbon sequestration in mafic and ultramafic reservoirs is a scalable strategy for dioxide removal, offering permanent storage via mineralization as stable carbonates. However, there limited information on the structure composition of key endpoints during sequestration. Here, we unravel atomic structure, composition, nanoscale morphology carbonates recovered from field-scale demonstration CO 2 basalt. Using transmission electron microscopy, mapped mineralogical variations...
XPS analyses of open shell ionic compounds, especially oxides the first row transition metals, for information such as oxidation state tend to focus on characteristics metal 2p features alone. These could be made considerably more robust with simultaneous characterization 3p well features. In these comments, we provide a perspective conceptual and theoretical framework needed extract chemical from complex multiplet structure Fe representative 3d oxides. We also present about novel kind...