A5019490372- Gold and Silver Nanoparticles Synthesis and Applications
- Plasmonic and Surface Plasmon Research
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
- Nanocluster Synthesis and Applications
- 2D Materials and Applications
- nanoparticles nucleation surface interactions
- Advanced biosensing and bioanalysis techniques
- Crystal Structures and Properties
- Physics of Superconductivity and Magnetism
- Inorganic Chemistry and Materials
- Electrocatalysts for Energy Conversion
- Protein Interaction Studies and Fluorescence Analysis
- Rare-earth and actinide compounds
- Graphene research and applications
- Nanomaterials for catalytic reactions
- Iron-based superconductors research
- Chalcogenide Semiconductor Thin Films
- Laser-Ablation Synthesis of Nanoparticles
- Catalytic Processes in Materials Science
- Advanced Electron Microscopy Techniques and Applications
- Spectroscopy Techniques in Biomedical and Chemical Research
- Advanced Condensed Matter Physics
- Near-Field Optical Microscopy
- Nonlinear Optical Materials Studies
University of Cambridge
2014-2025
Rice University
2014-2020
Northwestern University
2008-2013
Northwest University
2008-2012
The isolation of graphene in 2004 from graphite was a defining moment for the "birth" field: two-dimensional (2D) materials. In recent years, there has been rapidly increasing number papers focusing on non-graphene layered materials, including transition-metal dichalcogenides (TMDs), because new properties and applications that emerge upon 2D confinement. Here, we review significant advances important developments materials "beyond graphene". We provide insight into theoretical modeling...
Surface enhanced Raman spectroscopy (SERS) is a powerful vibrational technique that allows for highly sensitive structural detection of low concentration analytes through the amplification electromagnetic fields generated by excitation localized surface plasmons. SERS has progressed from studies model systems on roughened electrodes to sophisticated studies, such as single molecule spectroscopy. We summarize current state knowledge concerning mechanism and new substrate materials. highlight...
Recently, two-dimensional layers of transition metal dichalcogenides, such as MoS2, WS2, MoSe2, and WSe2, have attracted much attention for their potential applications in electronic optoelectronic devices. The selenide analogues MoS2 WS2 smaller band gaps higher electron mobilities, making them more appropriate practical However, reports on scalable growth high quality diselenide studies properties been limited. Here, we demonstrate the chemical vapor deposition (CVD) uniform MoSe2...
The cathodic oxygen reduction reaction (ORR) is essential in the electrochemical energy conversion of fuel cells. Here, through NH3 atmosphere annealing a graphene oxide (GO) precursor containing trace amounts Ru, we have synthesized atomically dispersed Ru on nitrogen-doped that performs as an electrocatalyst for ORR acidic medium. Ru/nitrogen-doped GO catalyst exhibits excellent four-electron activity, offering onset and half-wave potentials 0.89 0.75 V, respectively, vs reversible...
Metallic nanoparticles with strong optically resonant properties behave as nanoscale optical antennas, and have recently shown extraordinary promise light-driven catalysts. Traditionally, however, heterogeneous catalysis has relied upon weakly light-absorbing metals such Pd, Pt, Ru, or Rh to lower the activation energy for chemical reactions. Here we show that coupling a plasmonic nanoantenna directly catalytic enables light-induced generation of hot carriers within catalyst nanoparticles,...
Abstract Electrochemical reduction of CO 2 provides an opportunity to reach a carbon‐neutral energy recycling regime, in which emissions from fuel use are collected and converted back fuels. The is the first step toward synthesis more complex carbon‐based fuels chemicals. Therefore, understanding this crucial for development high‐performance electrocatalyst conversion higher order products such as hydrocarbons. Here, atomic iron dispersed on nitrogen‐doped graphene (Fe/NG) synthesized...
Single-molecule surface-enhanced Raman spectroscopy (SMSERS) of crystal violet (CV) has been reported since 1997, yet others have offered alternative explanations that do not necessarily imply SMSERS. Recently, the isotopologue approach, a statistically significant method to establish SMSERS, implemented for members rhodamine dye family. We provide first demonstration SMSERS triphenylmethane using approach. Two isotopologues CV are employed create chemically identical vibrationally distinct...
Localized surface plasmon resonances (LSPRs), resulting from the interaction of light with metal nanoparticles, are powerful tools for biological sensors, surface-enhanced spectroscopies, and optical devices. LSPR frequencies strongly dependent on a nanoparticle's structure, composition, local dielectric environment. However, these relationships prohibitively difficult or impossible to probe bulk solutions due heterogeneity chemically synthesized products. In this study, systematic...
This article provides a review of our recent studies single metal nanoparticles and nanoparticle clusters aimed at correlating the structural plasmonic properties same entity. The correlation between structure optical arising from localized surface plasmon resonance (LSPR) on various samples is described. Nanoparticles different materials (Ag Au) shapes (spheres, cubes, triangles) are considered. Experiments were carried out using transmission electron microscopy (TEM), dark-field...
Localized surface plasmon resonances are central to many sensing and signal transmission applications. Tuning of the energy line width through particle size shape is critical design such devices. To gain quantitative information on dependence plasmonic properties, mainly due retardation effects, we correlated optical spectra structures for 500 individual gold particles five different shapes. We show that effects dipolar frequency shape-independent when described by length, length over which...
We demonstrate the facile synthesis of high purity aluminum nanocrystals over a range controlled sizes from 70 to 220 nm diameter with size control achieved through simple modification solvent ratios in reaction solution. The monodisperse, icosahedral, and trigonal bipyramidal are air-stable for weeks, due formation 2-4 thick passivating oxide layer on their surfaces. show that support size-dependent ultraviolet visible plasmon modes, providing far more sustainable alternative gold silver...
Enriching the library of chiral plasmonic nanoparticles that can be chemically mass-produced will greatly facilitate applications plasmonics in areas ranging from constructing optical metamaterials to sensing molecules and activating immune cells. Here we report on a halide-assisted differential growth strategy direct anisotropic Au with tunable sizes diverse morphologies. Anisotropic nanodisks are employed as seeds yield triskelion-shaped threefold rotational symmetry high dissymmetry...
Interest in nanotechnology is driven by the unique and novel properties of nanoscale materials such as strong interaction metal particles with light, caused localized surface plasmon resonances (LSPRs). In this perspective article we review discuss prominent advantages advances single particle studies plasmonic nanostructures. Common techniques recent improvements spatial spectral resolution will first be outlined, covering both far-field near-field phenomena. Then, new insight information...
The Wulff construction is an invaluable tool to understand and predict the shape of nanoparticles. We demonstrate here that this venerable model, which gives a size-independent thermodynamic shape, becomes size dependent in nanoscale regime for alloy infinite reservoir approximation breaks down. improvements structure energetic modeling have wide-ranging implications both areas where energetics govern (e.g., nucleation growth) surface composition important heterogeneous catalysis).
Redox electrochemistry was used to reversibly tune the optical properties of plasmonic core-shell nanoparticles and dimers.
Wulff constructions are a powerful tool to predict the shape of nanoparticles, which strongly influences their performance in catalysis, sensing, and surface-enhanced spectroscopies. Previous models focused on energy minimization included contributions from surface energy, interface twin boundaries, segregation-induced bulk changes. However, large number shapes cannot be understood by such thermodynamic approaches, particular many twinned late transition metal (Ag, Au, Pt, Pd, etc.)...
Doped metal oxides are plasmonic materials that boast both synthetic and postsynthetic spectral tunability. They have already enabled promising smart window optoelectronic technologies been proposed for use in surface enhanced infrared absorption spectroscopy (SEIRA) sensing applications. Herein, we report the first step toward realization of former utilizing cubic F Sn codoped In2O3 nanocrystals (NCs) to couple C-H vibration surface-bound oleate ligands. Electron energy loss is used map...
Nanoparticles of some metals (Cu/Ag/Au) sustain oscillations their electron cloud called localized surface plasmon resonances (LSPRs). These can occur at optical frequencies and be driven by light, generating enhanced electric fields spectacular photon scattering. However, current plasmonic are rare, expensive, have a limited resonant frequency range. Recently, much attention has been focused on earth-abundant Al, but Al nanoparticles cannot resonate in the IR. The Mg reported here surmount...
Metal-semiconductor contact has been a critical topic in the semiconductor industry because it influences device performance remarkably. Conventional metals have served as major material electronic and optoelectronic devices, but such selection becomes increasingly inadequate for emerging novel materials two-dimensional (2D) materials. Deposited on semiconducting 2D channels usually form large resistance contacts due to high Schottky barrier. A few approaches reported reduce they are not...