J Environ Sci Health A Tox Hazard Subst Environ Eng
June 2024
Plant-mediated biosynthesis of nanoparticles is a green method that allows synthesis in one-pot process. Synthesis of gold nanoparticles with plant extracts has gained interest in the field of biomedicine due to its variety of applications. This study presents the synthesis green chemistry of gold nanoparticles (AuNPs) using the methanol extract of seeds.
View Article and Find Full Text PDFPFAS (poly- and per-fluorinated alkyl substances) represent a large family of recalcitrant organic compounds that are widely used and pose serious threats to human and ecosystem health. Here, palladium (Pd)-catalyzed defluorination and microbiological mineralization were combined in a denitrifying H-based membrane biofilm reactor to remove co-occurring perfluorooctanoic acid (PFOA) and nitrate. The combined process, i.
View Article and Find Full Text PDFAtomic structure prediction and associated property calculations are the bedrock of chemical physics. Since high-fidelity ab initio modeling techniques for computing the structure and properties can be prohibitively expensive, this motivates the development of machine-learning (ML) models that make these predictions more efficiently. Training graph neural networks over large atomistic databases introduces unique computational challenges, such as the need to process millions of small graphs with variable size and support communication patterns that are distinct from learning over large graphs, such as social networks.
View Article and Find Full Text PDFA systematic effort has been described to grow ternary GeSiSn semiconductors on silicon with high Sn concentrations spanning the 9.5-21.2% range.
View Article and Find Full Text PDFUnusual electrical transport properties associated with weak or strong localization are sometimes found in disordered electronic materials. Here, we report experimental observation of a crossover of electronic behavior from weak localization to enhanced weak localization due to the spatial influence of disorder induced by ZrO nanopillars in (LaSrMnO):(ZrO) (x = 0, 0.2, and 0.
View Article and Find Full Text PDFWhile co-oxidation is widely used to biodegrade halogenated organic pollutants (HOPs), a considerable amount of organic primary substrate is required. Adding organic primary substrates increases the operating cost and also leads to extra carbon dioxide release. In this study, we evaluated a two-stage Reduction and Oxidation Synergistic Platform (ROSP), which integrated catalytic reductive dehalogenation with biological co-oxidation for HOPs removal.
View Article and Find Full Text PDFMore food production required to feed humans will require intensive use of herbicides to protect against weeds. The widespread application and persistence of herbicides pose environmental risks for nontarget species. Elemental-palladium nanoparticles (PdNPs) are known to catalyze reductive dehalogenation of halogenated organic pollutants.
View Article and Find Full Text PDFDespite efforts to develop effective upconverting nanoparticle (UCNP) synthesis methods, there is still a need for approaches that are accessible and up-scalable while reproducibly providing fine control of UCNP size, crystallinity, and luminescence. This work presents a one-pot microwave-assisted strategy for synthesizing NaYF:Yb/Er UCNPs. A premixed rare earth (RE) solution in oleic acid (OA) was used to enhance repeatability while testing various synthesis conditions.
View Article and Find Full Text PDFLow-dimensional quantum materials that remain strongly ferromagnetic down to monolayer thickness are highly desired for spintronic applications. Although oxide materials are important candidates for the next generation of spintronics, ferromagnetism decays severely when the thickness is scaled to the nanometer regime, leading to deterioration of device performance. Here, a methodology is reported for maintaining strong ferromagnetism in insulating LaCoO (LCO) layers down to the thickness of a single unit cell.
View Article and Find Full Text PDFStrain engineering provides the ability to control the ground states and associated phase transition in epitaxial films. However, the systematic study of the intrinsic character and strain dependency in transition-metal nitrides remains challenging due to the difficulty in fabricating stoichiometric and high-quality films. Here the observation of an electronic state transition in highly crystalline antiferromagnetic CrN films with strain and reduced dimensionality is reported.
View Article and Find Full Text PDFIn the bulk, LaCoO_{3} (LCO) is a paramagnet, yet the low-temperature ferromagnetism (FM) is observed in tensile strained thin films, and its origin remains unresolved. Here, we quantitatively measured the distribution of atomic density and magnetization in LCO films by polarized neutron reflectometry (PNR) and found that the LCO layers near the heterointerfaces exhibit a reduced magnetization but an enhanced atomic density, whereas the film's interior (i.e.
View Article and Find Full Text PDFThe coexistence and coupling of ferroelasticity and magnetic ordering in a single material offers a great opportunity to realize novel devices with multiple tuning knobs. Complex oxides are a particularly promising class of materials to find multiferroic interactions due to their rich phase diagrams, and are sensitive to external perturbations. Still, there are very few examples of these systems.
View Article and Find Full Text PDFHere, a quantitative magnetic depth profile across the planar interfaces in BiFeO /La Sr MnO (BFO/LSMO) superlattices using polarized neutron reflectometry is obtained. An enhanced magnetization of 1.83 ± 0.
View Article and Find Full Text PDFThe spinel Li[Mn2]O4 is a candidate cathode for a Li-ion battery, but its capacity fades over a charge/discharge cycle of Li1-x[Mn2]O4 (0 < x < 1) that is associated with a loss of Mn to the organic-liquid electrolyte. It is known that the disproportionation reaction 2Mn(3+) = Mn(2+) + Mn(4+) occurs at the surface of a Mn spinel, and it is important to understand the atomic structure and composition of the surface of Li[Mn2]O4 in order to understand how Mn loss occurs. We report a study of the surface reconstruction of Li[Mn2]O4 by aberration-corrected scanning transmission electron microscopy.
View Article and Find Full Text PDFFilms of magnetic Ni@NiO core-shell nanoparticles (NPs, core diameter d ≅ 12 nm, nominal shell thickness variable between 0 and 6.5 nm) obtained with sequential layer deposition were investigated, to gain insight into the relationships between shell thickness/morphology, core-shell interface, and magnetic properties. Different values of NiO shell thickness t(s) could be obtained while keeping the Ni core size fixed, at variance with conventional oxidation procedures where the oxide shell is grown at the expense of the core.
View Article and Find Full Text PDFTo date, it is unclear whether chemical order (or disorder) is in any way connected to double exchange, electronic phase separation, or charge ordering (CO) in manganites. In this work, we carry out an atomic resolution study of the colossal magnetoresistant manganite La(2-2x)Sr(1+2x)Mn2O7 (LSMO). We combine aberration-corrected electron microscopy and spectroscopy with spectroscopic image simulations, to analyze cation ordering at the atomic scale in real space in a number of LSMO single crystals.
View Article and Find Full Text PDFPhysicochemical properties of transition metal oxides are directly determined by the oxidation state of the metallic cations. To address the increasing need to accurately evaluate the oxidation states of transition metal oxide systems at the nanoscale, here we present "Oxide Wizard." This script for Digital Micrograph characterizes the energy-loss near-edge structure and the position of the transition metal edges in the electron energy-loss spectrum.
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