A5040538807- Catalytic Processes in Materials Science
- Electronic and Structural Properties of Oxides
- Advancements in Solid Oxide Fuel Cells
- Advanced Nanomaterials in Catalysis
- Gas Sensing Nanomaterials and Sensors
- Advanced Materials Characterization Techniques
- Advanced Photocatalysis Techniques
- Copper-based nanomaterials and applications
- Electron and X-Ray Spectroscopy Techniques
- ZnO doping and properties
- Ion-surface interactions and analysis
- Nanocluster Synthesis and Applications
- Fuel Cells and Related Materials
- Nuclear Materials and Properties
- Semiconductor materials and devices
- Catalysis and Oxidation Reactions
- Electrochemical sensors and biosensors
- Diamond and Carbon-based Materials Research
- Electrocatalysts for Energy Conversion
- Analytical Chemistry and Sensors
- Carbon and Quantum Dots Applications
- Advanced Surface Polishing Techniques
- Advanced Electron Microscopy Techniques and Applications
- Graphene research and applications
- Geochemistry and Elemental Analysis
Pacific Northwest National Laboratory
2007-2019
Environmental Molecular Sciences Laboratory
2007-2019
Savitribai Phule Pune University
2015
University of Central Florida
2005-2012
Materials Processing (United States)
2005-2009
Hanbat National University
2009
Nanjing Normal University
2009
Defence Academy of the United Kingdom
2009
John Wiley & Sons (United States)
2007
FedEx (United States)
2007
A correlation between the particle size and lattice parameter has been established in nanocerium oxide particles (3–30nm). The variation is attributed to strain induced by introduction of Ce3+ due formation oxygen vacancies. Lattice was observed decrease with an increase size. ions concentration increased from 17% 44% reduction
We report the direct synthesis of cerium oxide nanoparticles (CNPs) in polyethylene glycol (PEG) based solutions with efficient radical scavenging properties. Synthesis CNPs PEG demonstrated a concentration dependent (of PEG) redox activity characterized by UV−visible spectroscopy. PEGylated acted as scavengers, and superoxide dismutase (SOD) synthesized various did not reduce compared to bare nanoceria. In addition superoxide, nanoceria quenching peroxide radicals well. It was observed that...
This review examines characterization challenges inherently associated with understanding nanomaterials and the roles surface interface methods can play in meeting some of challenges. In parts research community, there is growing recognition that studies published reports on properties behaviors often have reported inadequate or incomplete characterization. As a consequence, true value data these is, at best, uncertain. With increasing importance fundamental technological applications,it...
Increasingly, it is recognized that understanding and predicting nanoparticle behavior often limited by the degree to which particles can be reliably produced adequately characterized. Two examples demonstrate how sample preparation methods processing history may significantly impact particle are: 1) an examination of cerium oxide (ceria) reported in literature relation biological responses observed 2) observations related influence synthesis aging ceria nanoparticles. Examining data from...
The oxidation state switching of cerium in oxide nanoparticles is studied detail. influence synthesis medium, aging time, and local environment on the switching, between +3 +4, analyzed by tracking absorption edge using UV–visible spectroscopy. It observed that tuning environment, chemistry could be altered. These time-dependent, environmentally induced changes likely contribute to inconsistencies literature regarding quantum-confinement effects for ceria nanoparticles. results this Article...
Abstract Nanostructured materials are increasingly subject to nearly every type of chemical and physical analysis possible. Due their small sizes, there is a significant focus on tools with high spatial resolution. It also natural characterize nanomaterials using designed analyze surfaces, because surface area. Regardless the approach, nanostructured present variety obstacles adequate, useful, needed analysis. Case studies measurements ceria iron metal‐core/oxide‐shell nanoparticles used...
Nanoceria has shown excellent biomedical properties for potential use in treatment of diseases caused by reactive oxygen species (ROS). In the present work, synthesis and redox chemistry nanoceria presence polyhydroxyl groups such as glucose dextran are reported. The effect both acidic basic medium on oxidation state stability absence buffer was examined using UV−vis spectroscopy transmission electron microscopy. mediums show a difference terms size structure without interfering with...
A Au-CeO2 nanocomposite film has been investigated as a potential sensing element for high-temperature plasmonic of H2, CO, and NO2 in an oxygen containing environment. The CeO2 thin was deposited by molecular beam epitaxy (MBE), Au implanted into the as-grown at elevated temperature followed high annealing to form well-defined nanoclusters. characterized X-ray diffraction (XRD) Rutherford backscattering spectrometry (RBS). For gas experiments, separate exposures varying concentrations were...
A room temperature, template-free, wet chemical synthesis of ceria nanoparticles and their long term ageing characteristics are reported. High resolution transmission electron microscopy UV-visible spectroscopy techniques used to observe the variation in size, structure oxidation state, respectively as a function time. The morphology hierarchical assembly (octahedral superstructure) nanostructures imputed inherent structural aspects cerium oxide. It is hypothesized that 3-5 nm individual...
Abstract The formation of nanorods, driven by the physicochemical phenomena during freezing and after aging frozen ceria nanoparticle suspensions, is reported. During a dilute aqueous solution CeO 2 nanocrystals, some nuclei remain in while others are trapped inside micro‐ nanometer voids formed within growing ice front. Over time (2–3 weeks) particles nanometer‐wide combine an oriented attachment process to form nanorods. experimental observations consistent with molecular dynamics...
The effect of radiation on the oxidation state Ce in high-quality single and polycrystalline ceria thin films is presented. were synthesized by molecular beam epitaxy irradiated with high energy ionizing 2 MeV He+ ions varying flux density. surface chemistry was characterized situ X-ray photoelectron spectroscopy (XPS). Upon irradiation, concentration Ce3+ increased 13 19% ceria, respectively. Molecular dynamics simulation thermal spikes displacement cascade damage provide details induced...
Growth rate-induced epitaxial orientations and crystalline quality of CeO2 thin films grown on Al2O3(0001) by oxygen plasma-assisted molecular beam epitaxy were studied using in situ ex characterization techniques. grows as three-dimensional (3D) islands two-dimensional layers at growth rates 1–7 Å/min ≥9 Å/min, respectively. The formation CeO2(100) CeO2(111) occurs 1 Glancing-incidence x-ray diffraction measurements have shown that the intermediate (2–7 Å/min) consist polycrystalline along...
The heat transfer characteristics of silica (SiO2), ceria (CeO2), and alumina (Al2O3) nanofluids at 0.5% concentration particle size 10nm 20 nm in pool boiling have been analyzed. influence acidity on has studied. pH value the nanosuspensions is important from point view that it determines stability particles, their mutual interactions towards wire. When there no deposition wire, nanofluid with any oxide suspension increases CHF by about 50% within uncertainty limits regardless type its...
Analysis of nanoparticles is often challenging especially when they are embedded in a matrix. Hence, we have used laser-assisted atom probe tomography (APT) to analyze the Au nanoclusters synthesized situ using ion-beam implantation single crystal MgO APT analysis along with scanning transmission electron microscopy and energy dispersive spectroscopy (STEM-EDX) indicated that an average size ∼ 8–12 nm. While it difficult composition individual STEM, can give three-dimensional compositions...
Experimental and theoretical investigations were performed to investigate the effect of water on optical properties nanoceria as a function Ce<sup>3+</sup> concentration.
High-quality CeO2 films were grown on Al2O3(0001) substrates using oxygen plasma-assisted molecular beam epitaxy. The epitaxial orientation of the is found to be CeO2(100) and CeO2(111) at low (&lt;8 Å/min) higher growth rates (&gt;12 Å/min), respectively. film grows as three-dimensional islands, while two-dimensional layers. exhibits better quality compared film. However, shows three in-plane domains 30° each other. While attributed close match between sublattices Al2O3(0001), in...
A combination of long-term aging studies and molecular dynamics (MD) simulations has been successfully used to explain the time-dependent hierarchical assembly ceria nanoparticles (CNPs). When CNPs were aged in as-synthesized condition at room temperature water, it was observed that individual 3−5 nm result octahedral superstructures through a fractal assembly. This self-assembly despite absence any surfactant, temperature, under atmospheric pressure. High resolution transmission electron...