We report a general approach to NiAu alloy nanoparticles (NPs) by co-reduction of Ni(acac)2 (acac = acetylacetonate) and HAuCl4·3H2O at 220 °C in the presence of oleylamine and oleic acid. Subject to potential cycling between 0.6 and 1.0 V (vs reversible hydrogen electrode) in 0.5 M H2SO4, the NiAu NPs are transformed into core/shell NiAu/Au NPs that show much enhanced catalysis for hydrogen ev...

The structure of metal nanoparticles embedded inside dielectric nanowires/nanotubes, namely nanopeapods, has been of increasing interest due to their unusual photoresponse and optical adsorption properties. This paper presents a type of new inorganic nanopeapod: faceted Au nanoparticles inside MgO nanowires. The Au self-assembles into a nanoparticle chain during the vapor-liquid-solid growth of...

We review our recent results on the growth and characterization of silicon nanowires (SiNWs). Vapourphase deposition techniques are considered, including chemical vapour deposition (CVD), plasma-enhanced chemical vapour deposition (PECVD), high-temperature annealing, and thermal evaporation. We present complementary approaches to SiNW production. We investigate the low-temperature (down to 300 ...

The oxidation of different alcohols with molecular oxygen in water has been investigated using a range of activated carbon-supported Au-Pd bimetallic catalysts. The effect of the Au-Pd ratio on the conversion and selectivity was observed and a synergistic effect is present in a large range of the Au-Pd ratio, being maximized for Au80-Pd20 composition instead of Au90-Pd10 shown in glycerol oxida...

We pursue the goal of providing fundamental atomistic understanding of metal oxide and metal sulfide nanostructures supported on metal substrates. Such systems are important as model systems for heterogeneous catalysts and allow better understanding of epitaxial 2D materials, such as MoS2 in contact with a metal. By focusing on what happens on the atomiclevel we can for example evaluate the rol...

Poly(vinyl alcohol) (PVA)-stabilized Au nanoparticles (NPs) were synthesized by colloidal methods in which temperature variations (−75 to 75 °C) and mixed H2O/EtOH solvent ratios (0, 50, and 100 vol/vol) were used. The resulting Au NPs were immobilized on TiO2 (P25), and their catalytic performance was investigated for the liquid phase oxidation of glycerol. For each unique solvent system, ther...

An atomic-level strategy is devised to gain insight into the origin of nanogold catalysis by using atomically monodisperse Au(n)(SR)(m) nanoclusters as well-defined catalysts for styrene oxidation. The Au(n)(SR)(m) nanoclusters are emerging as a new class of gold nanocatalyst to overcome the polydispersity of conventional nanoparticle catalysts. The unique atom-packing structure and electronic ...

It has been reported that Pd-Au bimetallic catalysts display improved catalytic performance after adequate calcination. In this study, a model catalyst study was conducted to investigate the effects of annealing in oxygen on the surface structures of Pd-Au alloys by comparing the physicochemical properties of Pd/Au(111) surfaces that were annealed in ultrahigh vacuum (UHV) versus in an oxygen a...

Controlled synthesis of Au nanoparticles with adjustable sizes (10-50 nm) and narrow size distributions (<10% in standard deviation) was realized by reducing hydrochloroauric acid with R-cyclodextrin (R-CD) in an alkaline aqueous solution, which was very simple and “green”. It was revealed that a proper pH was essential to the formation of stable dispersions of nonaggregated Au nanoparticles an...