A5100671232- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- Magnetic and transport properties of perovskites and related materials
- Advanced Condensed Matter Physics
- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Magnetic properties of thin films
- Advancements in Battery Materials
- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Electrocatalysts for Energy Conversion
- Advanced Battery Materials and Technologies
- Semiconductor materials and devices
- Iron-based superconductors research
- Catalytic Processes in Materials Science
- 2D Materials and Applications
- Graphene research and applications
- Advanced Materials Characterization Techniques
- Rare-earth and actinide compounds
- Advanced X-ray Imaging Techniques
- Magnetic Properties and Applications
- Superconductivity in MgB2 and Alloys
- Advanced battery technologies research
- Surface and Thin Film Phenomena
- ZnO doping and properties
Brookhaven National Laboratory
2016-2025
Stony Brook University
2016-2025
Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine
2025
Chinese Academy of Sciences
2010-2023
University of Chinese Academy of Sciences
2023
Zhejiang Shuren University
2023
Institute of Modern Physics
2023
Center for Functional Nanomaterials
2004-2022
Anhui University
2022
Material Sciences (United States)
2017-2021
Extending Platinum Catalysts performs extremely well as a catalyst for the oxygen-reduction reaction that runs under highly acidic conditions in proton-exchange membrane fuel cells, but is expensive. One strategy reducing costs to increase surface area of platinum. Lim et al. (p. 1302 , published online 14 May) describe simple chemical route, which Pt ions solution are reduced onto Pd seed crystals, creates faceted nanocrystals with high owing their dendritic architecture. On mass basis,...
Not noble but effective: A new class of heterogeneous hydrogen-evolving electrocatalysts based on inexpensive components was developed. The carbon-supported nickel–molybdenum nitride (NiMoNx, see picture) catalyst had a nanoscale sheet structure comprising few layers and an abundance highly accessible reactive sites.
It is well-known that inorganic nanocrystals are a benchmark model for nanotechnology, given the tunability of optical properties and stabilization specific phases uniquely possible at nanoscale. Copper (I) oxide (Cu2O) metal semiconductor with promising applications in solar energy conversion catalysis. To understand Cu/Cu2O/CuO system nanoscale, we have developed method preparing highly uniform monodisperse Cu2O. The procedure also serves to demonstrate our development generalized...
MoS2 presents a promising low-cost catalyst for the hydrogen evolution reaction (HER), but understanding about its active sites has remained limited. Here we present an unambiguous study of catalytic activities all possible MoS2, including edge sites, sulfur vacancies, and grain boundaries. We demonstrate that, in addition to well-known catalytically vacancies provide another major site HER, while activity boundaries is much weaker. The intrinsic turnover frequencies (Tafel slopes) are...
We examined the effects of thickness Pt shell, lattice mismatch, and particle size on specific mass activities from changes in effective surface area activity for oxygen reduction induced by stepwise Pt-monolayer depositions Pd Pd(3)Co nanoparticles. The core-shell structure was characterized at atomic level using Z-contrast scanning transmission electron microscopy coupled with element-sensitive energy loss spectroscopy. enhancements are largely attributed to compressive strain effect based...
Abstract Lattice oxygen can play an intriguing role in electrochemical processes, not only maintaining structural stability, but also influencing electron and ion transport properties high-capacity oxide cathode materials for Li-ion batteries. Here, we report the design of a gas–solid interface reaction to achieve delicate control activity through uniformly creating vacancies without affecting integrity Li-rich layered oxides. Theoretical calculations experimental characterizations...
Abstract This article provides an overview of recent developments regarding synthesis Pd nanocrystals with well‐controlled shapes in aqueous solutions. In a solution‐phase synthesis, the final shape taken by nanocrystal is determined twin structures seeds and growth rates different crystallographic facets. Here, maneuvering these factors system to achieve control for discussed. L ‐ascorbic acid, citric poly(vinyl pyrrolidone) are tested manipulating reduction kinetics, acid Br – ions used as...
Materials that undergo a conversion reaction with lithium (e.g., metal fluorides MF(2): M = Fe, Cu, ...) often accommodate more than one Li atom per transition-metal cation, and are promising candidates for high-capacity cathodes ion batteries. However, little is known about the mechanisms involved in process, origins of large polarization during electrochemical cycling, why some materials reversible FeF(2)) while others not CuF(2)). In this study, we investigated binary fluorides, FeF(2)...
Abstract The thermal instability of the cathode materials in lithium‐ion batteries is an important safety issue, requiring incorporation several approaches to prevent runaway and combustion. Systematic studies, using combined well‐defined situ techniques, are crucial obtaining in‐depth understanding structural origin this overcharged materials. Here time‐resolved X‐ray diffraction, absorption, mass spectroscopy, high‐resolution transmission electron microscopy during heating detail changes...
Graphene-modified LiFePO4 composite has been developed as a Li-ion battery cathode material with excellent high-rate capability and cycling stability. The was prepared nanoparticles graphene oxide nanosheets by spray-drying annealing processes. primary embedded in micro-sized spherical secondary particles were wrapped homogeneously loosely 3D network. Such special nanostructure facilitated electron migration throughout the particles, while presence of abundant voids between sheets beneficial...
In this Letter we show that superconducting ${\mathrm{Fe}}_{1.01}\mathrm{Se}$ undergoes a structural transition at 90 K from tetragonal to an orthorhombic phase but nonsuperconducting ${\mathrm{Fe}}_{1.03}\mathrm{Se}$ does not. High resolution electron microscopy low temperatures further reveals unexpected additional modulation of the crystal structure involves displacements Fe atoms, and composition shows different, complex nanometer-scale modulation. Finally, magnetism is not driving force...
This paper provides direct evidence to support the role of a capping agent in controlling evolution Ag seeds into nanocrystals with different shapes. Starting single-crystal (spherical or cubic shape), we could selectively obtain octahedrons enclosed by {111} facets and nanocubes/nanobars {100} adding sodium citrate (Na3CA) poly(vinyl pyrrolidone) (PVP), respectively, as while all other parameters were kept same. research not only offers new insights played shape-controlled synthesis but...
A wide range of interferometric techniques recover phase information that is mathematically wrapped on the interval (-pi, pi). Obtaining true unwrapped a longstanding problem. We present an algorithm solves unwrapping problem, using combination Fourier techniques. The execution time for our equivalent to computation required performing eight fast transforms and stable against noise residues in phase. have extended handle data arbitrary size. expect state art existing applications, including...
The production of hydrogen from water electrolysis calls for an efficient non-precious-metal catalyst to make the process economically viable because high cost and limited supply currently used platinum catalysts. Here we present such a made earth-abundant molybdenum common, humble soybeans (MoSoy). This catalyst, composed catalytic β-Mo2C phase acid-proof γ-Mo2N phase, drives evolution reaction (HER) with low overpotentials, is highly durable in corrosive acidic solution over period...
Fast-charging batteries typically use electrodes capable of accommodating lithium continuously by means solid-solution transformation because they have few kinetic barriers apart from ionic diffusion. One exception is titanate (Li4Ti5O12), an anode exhibiting extraordinary rate capability apparently inconsistent with its two-phase reaction and slow Li diffusion in both phases. Through real-time tracking Li+ migration using operando electron energy-loss spectroscopy, we reveal that facile...
Abstract Néel skyrmions are of high interest due to their potential applications in a variety spintronic devices, currently accessible ultrathin heavy metal/ferromagnetic bilayers and multilayers with strong Dzyaloshinskii–Moriya interaction. Here we report on the direct imaging chiral spin structures including an exchange-coupled cobalt/palladium multilayer at room temperature Lorentz transmission electron microscopy, high-resolution technique previously suggested exhibit no skyrmion...
Core-shell nanoparticles increasingly are found to be effective in enhancing catalytic performance through the favorable influence of core materials on active components at surface. Yet, sustaining high activities under operating conditions often has proven challenging. Here we explain how differences components' diffusivity affect formation and stability core-shell hollow nanostructures, which ascribe Kirkendall effect. Using Ni as templates, fabricated compact smooth Pt nanocrystals that...
Ni‐rich layered oxides (LiNi 1– x M O 2 ; = Co, Mn, …) are appealing alternatives to conventional LiCoO as cathodes in Li‐ion batteries for automobile and other large‐scale applications due their high theoretical capacity low cost. However, preparing stoichiometric LiNi with ordered layer structure reversible capacity, has proven difficult cation mixing octahedral sites. Herein, situ studies of synthesis reactions the associated structural ordering LiNiO Co‐substituted variant, 0.8 Co 0.2 ,...
Using a combination of time-resolved X-ray diffraction (XRD), in situ transmission electron microscopy (TEM), and first principles calculations, we explore the structural origin overcharge induced thermal instability two cathode materials, LiNi0.8Co0.15Al0.05O2 LiNi1/3Co1/3Mn1/3O2, which exhibit significant difference stabilities. Detailed TEM analysis reveals, for time, complex core–shell-surface structure particles both materials that was not previously detected by XRD. Structural...
Direct mapping of the lithium spatial distribution and chemical state provides critical information on structure-correlated transport in electrode materials for batteries. Nevertheless, probing lithium, lightest solid element periodic table, poses an extreme challenge with traditional X-ray or electron scattering techniques due to its weak power vulnerability radiation damage. Here, we report nanoscale maps electrochemically lithiated graphite using energy loss spectroscopy transmission...
Diverse parallel stitched 2D heterostructures, including metal-semiconductor, semiconductor-semiconductor, and insulator-semiconductor, are synthesized directly through selective "sowing" of aromatic molecules as the seeds in chemical vapor deposition (CVD) method. The methodology enables large-scale fabrication lateral which offers tremendous potential for its application integrated circuits.
Na<sup>+</sup>diffuses and re-dissolves into matrix grains, resulting in carrier concentration modulation thereby superior high temperature TE performances.