Interface Catalysts of Ni/CoN for Hydrogen Electrochemistry.

The development of active, durable, and nonprecious electrocatalysts for hydrogen electrochemistry is highly desirable but challenging. In this work, we design and fabricate a novel interface catalyst of Ni and CoN (Ni/CoN) for hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR). The Ni/CoN interfacial catalysts not only achieve a current density of -10.

Excitation Wavelength-Dependent Photoluminescence Decay of Hybrid Gold/Quantum Dot Nanostructures.

Hybrid nanostructures comprised of metal nanoparticles (MNPs) and quantum dots (QDs) have been found to exhibit unique, new optical properties due to the interaction that occurs between the MNPs and QDs. The aim of this work is to understand how the exciton-plasmon interaction in these systems is dependent on the excitation wavelength. The nanoassemblies consisted of gold (Au) NPs coated in a silica (SiO) shell of a controlled thickness and core/shell CdSe/CdS QDs adsorbed onto the SiO shells.

Au-Cu-M (M = Pt, Pd, Ag) nanorods with enhanced catalytic efficiency by galvanic replacement reaction.

This work reports a general wet-chemistry method to produce Au-Cu-X (X = Pt, Pd, and Ag) trimetallic nanorods using galvanic replacement reaction with Au-Cu nanorods as the templates. The mild conditions, such as low temperature and slow injection of metal precursors, contributed to the slow galvanic replacement reaction and helped keep the rod structure intact. The distribution of Au, Cu and the doping metals was even in the rods as confirmed by elemental mapping.

Formation of bimetallic dumbbell shaped particles with a hollow junction during galvanic replacement reaction.

The galvanic replacement reaction (GRR) has been shown to be an effective method to fine tune the structure of monometallic nanoparticles by controlling the precursor concentration and surface ligands. However, the structural evolution of nanoparticles is not well understood in multimetallic systems, where along with oxidation, dealloying and diffusion occur simultaneously. Here, we demonstrate that by controlling the rate of GRR in AuCu alloy nanorods, they can be transformed into either AuCu hollow rods or AuCu@Au core-shell spheroids.

An unconventional mechanism of hollow nanorod formation: asymmetric Cu diffusion in Au-Cu alloy nanorods during galvanic replacement reaction.

This study investigates how AuCu3 alloy nanorods transform into hollow rods during a galvanic replacement reaction. An unusual reaction intermediate was observed where the solid nanorod became partially hollow and Cu rich at one end. This was attributed to simultaneous galvanic replacement and asymmetric diffusion of Cu due to the Kirkendall effect.

Structural defect induced peak splitting in gold-copper bimetallic nanorods during growth by single particle spectroscopy.

A single particle level study of bimetallic nanoparticle growth provides valuable information that is usually hidden in ensemble measurements, helping to improve the understanding of a reaction mechanism and overcome the synthetic challenges. In this study, we use single particle spectroscopy to monitor the changes in the scattering spectra of Au-Cu alloy nanorods during growth. We found that the unique features of the single particle scattering spectra were due to atomic level geometric defects in the nanorods.

Synthesis, characterization and photoluminescence of cdS hyperbranched nanocrystals by a simple solution chemistry method.

We report the synthesis of CdS hyperbranched nanocrystals using a simple hot coordination solvents method. Transmission electron microscopy studies showed that the length of the arms and the angle of branching could be controlled by varying organic surfactants in terms of amount and type. It was found that long chain carboxylic acids favored the synthesis of CdS hyperbranched nanocrystals.

Trioctylphosphine as Both Solvent and Stabilizer to Synthesize CdS Nanorods.

High quality CdS nanorods are synthesized reproducibly with cadmium acetate and sulfur as precursors in trioctylphosphine solution. The morphology, crystalline form and phase composition of CdS nanorods are characterized by transmission electron microscopy (TEM), high-resolution TEM and X-ray diffraction (XRD). CdS nanorods obtained are uniform with an aspect ratio of about 5:1 and in a wurtzite structure.

Highly ordered self-assembly with large area of Fe3O4 nanoparticles and the magnetic properties.

Monodisperse Fe3O4 nanoparticles (NPs) with narrow size distribution are synthesized by a high-temperature solution-phase method. The diameter of the as-synthesized NPs is tuned from 2 to 14 nm by varying the reaction conditions. Highly ordered superlattice structures of the Fe3O4 NPs with areas extending over 0.

Morphologies and microstructures of nano-sized Cu(2)O particles using a cetyltrimethylammonium template.

Hollow polyhedra and cubes of nanostructured Cu(2)O particles have been synthesized by reduction of CuSO(4) with ascorbate acid in the solution phase. The nanostructures were obtained when the cetyltrimethylammonium (CTAB) concentration ranged from 0 to 0.03 M in the presence of NaOH.