Core−shell nanocomposites based on Au nanoparticle@zinc−ironembedded porous carbons (Au@Zn−Fe−C) derived from metal−organic frameworks were prepared as bifunctional electrocatalysts for both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). A single Au nanoparticle of 50−100 nm in diameter was encapsulated within a porous carbon shell embedded with Zn−Fe compounds. The resu...

We are presenting a combinatorial approach for the preparation of surface-adsorbed metal nanoparticles for investigation of biological phenomena. Metal nanoparticles, in particular noble metal nanoparticles, have become increasingly recognized for their importance in studies of biological systems. An intense near-field associated with these particles can be exploited to improve the performance ...

The present industrial sector related to textile industry, medicine product industry, house hold industry have enormously spread the use of Silver nanoparticle. Varieties of teratogenic effects are executed due to silver nanoparticle among which one of the important is skeletal dysmorphology. The discovery of the new facts can be compared with the quotes from some studies [1] reveals that there...

Energy migrations at metal nanomaterial surfaces are fundamentally important to heterogeneous reactions. Here we report two distinctive energy migration pathways of monolayer adsorbate molecules on differently sized metal nanoparticle surfaces investigated with ultrafast vibrational spectroscopy. On a 5 nm platinum particle, within a few picoseconds the vibrational energy of a carbon monoxide a...

While a large number of microbial species are capable of producing metal NPs, mechanism of nanoparticle biosynthesis is very important. The metabolic complexity of viable microorganisms complicates the analysis and identification of active species in the nucleation and growth of metal NPs. Strategies such as enzymatic oxidation or reduction, sorption on the cell wall and, in some cases, subsequ...

We study finite-size effects in surface-enhanced Raman scattering (SERS) from molecules adsorbed on small metal particles. Within an electromagnetic description of SERS, the enhancement of the Raman signal originates from the local field of the surface plasmon resonance in a nanoparticle. With decreasing particle sizes, this enhancement is reduced due to the size-dependent Landau damping of the...

The binding of clusters of metal nanoparticles is partly electrostatic. We address difficulties in calculating the electrostatic energy when high charging energies limit the total charge to a single quantum, entailing unequal potentials on the particles. We show that the energy at small separation h has a singular logarithmic dependence on h. We derive a general form for this energy in terms of...

We present a microscopic theory of quantum-size effects in surface-enhanced Raman scattering (SERS) from molecules adsorbed on small metal nanoparticles. In noble-metal nanoparticles, the confining potential has different effect on s-band and d-band electrons. Namely, the spillout of delocalized sp-electrons beyond the classical nanoparticle boundary results in an incomplete embedding of s-elec...

The ability to assemble nanoparticles into functional structures is an important challenge that needs to be addressed for the generation of nanoparticle-based devices. Sol-gel method represents a facile yet powerful strategy for the self-assembly of metal oxides, chalcogenides, and metal-semiconductor hybrid nanoparticle systems into three-dimensionally connected porous nanostructures. In contr...

The ability of short pulse laser ablation in liquids to produce clean colloidal nanoparticles and unusual surface morphology has been employed in a broad range of practical applications. In this paper, we report the results of large-scale molecular dynamics simulations aimed at revealing the key processes that control the surface morphology and nanoparticle size distributions by pulsed laser ab...