Seoul National University · 材料科学
Professor Megalamane S. Bootharaju's research lab specializes in the design, synthesis, and characterization of atomically precise noble and non-noble metal nanomaterials, with a focus on their environmental and optoelectronic applications. The lab investigates the fundamental interactions between nanomaterials—particularly silver and gold clusters and nanoparticles—and environmental pollutants such as pesticides, heavy metals, and organic contaminants, aiming to develop efficient water purification strategies. A key research direction involves understanding structure-property relationships in nanoclusters, including doping strategies and near-infrared luminescence, using advanced spectroscopic and microscopic techniques. The lab also explores the role of capping ligands and support matrices in stabilizing and tuning the reactivity of these nanosystems.
Figures are computed from collected data and may differ slightly.
Application of nanoparticles (NPs) in environmental remediation such as water purification requires a detailed understanding of the mechanistic aspects of the interaction between the species involved. Here, an attempt was made to understand the chemistry of noble metal nanoparticle-pesticide interaction, as these nanosystems are being used extensively for water purification. Our model pesticide, chlorpyrifos (CP), belonging to the organophosphorothioate group, is shown to decompose to 3,5,6-tric
We have studied the chemical interaction of heavy metal ions such as Hg(II), Hg(I), Pb(II), and Cd(II) of various concentrations with naked and protected silver nanoparticles (Ag@citrate and Ag@MSA, respectively, where MSA is mercaptosuccinic acid). The particles were of 30 and 8 nm diameter, respectively. We observed that the metal ions interact with both the core of the nanoparticles and the functional groups of the capping agents. We study the effects of interaction using spectroscopic and mi
While there are numerous recent reports on doping of a ligand-protected noble metal nanocluster (e.g., Au and Ag) with another noble metal, non-noble metal (e.g., Cd) doping remains challenging. Here, we design a phosphine-assisted synthetic strategy and synthesize a Cd doped Ag nanocluster, Cd<sub>12</sub>Ag<sub>32</sub>(SePh)<sub>36</sub> (SePh: selenophenolate), which exhibits characteristic UV-vis absorption features and rare near-infrared (NIR) photoluminescence at ∼1020 nm. The X-ray singl
We report a facile and rapid (less than 15 min) synthesis of atomically precise, dithiol-protected, silver quantum cluster, Ag7(DMSA)4 (DMSA: meso-2,3-dimercaptosuccinic acid), through a modified solid state route. The as-synthesized cluster exhibits molecular optical absorption features with a prominent λmax at ~500 nm. Composition of the cluster was confirmed using various spectroscopic and microscopic techniques such as electrospray ionization mass spectrometry (ESI MS), X-ray photoelectron s
We report the chemical interactions of unsupported and alumina-supported Ag(7) and Ag(8) clusters protected with MSA (mercaptosuccinic acid) with heavy metal ions Hg(II), Cd(II), and Pb(II) in water at different concentrations. The investigation was carried out to determine the feasibility of this interesting new class of materials called quantum clusters for water purification. These systems were studied using various spectroscopic and microscopic techniques such as ultraviolet-visible spectros
Metal chalcogenide nanomaterials have gained widespread interest in the past two decades for their potential optoelectronic, energy, and catalytic applications. The colloidal growth of various forms of these materials, such as nanowires, platelets, and lamellar assemblies, proceeds through certain thermodynamically stable, ultrasmall (<2 nm) intermediates called magic-sized nanoclusters (MSCs). Due to quantum confinement and its resultant intriguing properties, isolation or direct synthesis of M
Although atomically precise metalloid nanoclusters (NCs) of identical size with distinctly different molecular structures are highly desirable to understand the structural effects on the optical and photophysical properties, their synthesis remains highly challenging. Herein, we employed phosphine and thiol capping ligands featuring appropriate steric effects and synthesized a charge-neutral Ag NC with the formula Ag<sub>44</sub> (EBT)<sub>26</sub> (TPP)<sub>4</sub> (EBT: 2-ethylbenzenethiolate;
We describe the degradation of chlorocarbons (CCl4, C6H5CH2Cl and CHCl3) in solution at room temperature (27 ± 4 °C) by the monolayer-protected silver quantum cluster, Ag9MSA7 (MSA: mercaptosuccinic acid) in the presence of isopropyl alcohol (IPA). The main degradation products were silver chloride and amorphous carbon. Benzyl chloride was less reactive towards clusters than CCl4 and CHCl3. Materials used in the reactions and the reaction products were characterized using several spectroscopic a
In this work, we use dark-field optical microscopy (DFM) and hyper spectral imaging (HSI) to study the interactions of single Ag and Au nanoparticles (NPs) with Hg2+ in real time, at room temperature (25 °C). NPs were immobilized on glass substrates using 3-aminopropyltrimethoxysilane (APTMS) as the anchoring agent. Red, green and blue colors were assigned to the particles in hyper spectral images on the basis of their relative scattering intensities at 640, 550 and 460 nm, where the particles s
Understanding the effect of internal atoms in metal nanoparticles on heterogeneous catalytic processes is crucial for achieving high activity and selectivity. This requires meticulous synthetic control over the size, composition, and atomic arrangement of nanoparticles. Here, we report the design of ligand-exchange-induced structure transformation and nanomolecule-templated atomic-level galvanic exchange strategies to synthesize PtAg<sub>24</sub>(IPBT)<sub>18</sub> (denoted as PtAg<sub>24</sub>)
The integration of organometallic compounds with metal nanoparticles can, in principle, generate hybrid nanocatalysts endowed with augmented functionality, presenting substantial promise for catalytic applications. Herein, we synthesize an atomically precise metal cluster (Ag<sub>9</sub>Cu<sub>6</sub>) catalyst integrated with alkynylferrocene molecules (Ag<sub>9</sub>Cu<sub>6</sub>-Fc). This hybrid catalyst design facilitates a continuous electron transfer channel via an ethynyl bridge and esta
Ligand protected metal nanoclusters (NCs) are an emerging class of functional materials with intriguing photophysical and chemical properties. The size and molecular structure play an important role in endowing NCs with characteristic optical and electronic properties. Modulation of these properties through the chemical reactivity of NCs is largely unexplored. Here, we report on the synthesis of self-assembled Ag<sub>2</sub>Cl<sub>2</sub>(dppe)<sub>2</sub> clusters through the ligand-exchange-in
Abstract Although atomically precise metalloid nanoclusters (NCs) of identical size with distinctly different molecular structures are highly desirable to understand the structural effects on the optical and photophysical properties, their synthesis remains highly challenging. Herein, we employed phosphine and thiol capping ligands featuring appropriate steric effects and synthesized a charge‐neutral Ag NC with the formula Ag 44 (EBT) 26 (TPP) 4 (EBT: 2‐ethylbenzenethiolate; TPP: triphenylphosph
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