Prior experimental work had found that the Fermi level at InN growth surfaces is pinned well above the conduction band edge, leading to strong surface band bending and electron accumulation. Using cross-sectional scanning photoelectron microscopy and spectroscopy, we show definitive evidence of unpinned Fermi level for in situ cleaved a-plane InN surfaces. To confirm the presence or absence of ...

Nanoscale gold−titania (Au/TiO2) catalysts may provide the right combination of electronic structure, structural dynamics, and stability to facilitate wide ranging chemical transformations, including reactions for utilization of renewable energy sources. The Au/TiO2based systems have also emerged as promising photocatalysts capable of promoting light-induced production of hydrogen and other ren...

Reactivity of sub 1 nm supported clusters: (TiO2)(n) clusters supported on rutile TiO2 (110) Author(s) Iwaszuk, Anna; Nolan, Michael Publication date 2011-02 Original citation IWASZUK, A. & NOLAN, M. 2011. Reactivity of sub 1 nm supported clusters: (TiO2)n clusters supported on rutile TiO2 (110). Physical Chemistry Chemical Physics, 13, 4963-4973. doi: 10.1039/C0CP02030C Type of publication Art...

Although CdS and PbS quantum dot-sensitized TiO2 nanotube arrays (TNTAs/QDs) show photocatalytic activity in the visible-light region, the low internal quantum efficiency and the slow interfacial hole transfer rate limit their applications. This work modified the surface of the TNTAs/QDs photoelectrodes with metal-oxide overlayers by atomic layer deposition (ALD), such as coating Al2O3, TiO2, a...

Variable temperature scanning tunneling microscopy (STM) has been used to image oxide-supported nanoclusters of Au at temperatures from 300 to 450 K and oxygen pressures from 10−10 to 4 Torr. Oxygen-induced morphological changes of the TiO2(1 × 2) reconstruction are apparent at room temperature and prolonged exposure (∼3 × 103 L (langmuir)) at 10−4 Torr oxygen. Gold clusters with diameters smal...

Au-TiO2 snowman-like heterodimer nanoparticles were prepared by a surface sol-gel process based on gold Janus nanoparticles whose surface-protecting monolayers consisted of a hemisphere of hydrophobic 1-hexanethiolates and the other of hydrophilic 2-(2-mercaptoethoxy)ethanol. Transmission electron microscopic measurements showed that the resulting TiO2 nanoparticles (diameter 6 nm) exhibited we...

The Turkevich synthesis method of Au nanoparticles (AuNPs) was adopted for direct fabrication of SiO2@Au and TiO2@Au core-shell nanostructures. In this method, chloroauric acid was reduced with trisodium citrate in the presence of amine-functionalized silica or titania submicroparticles. Core-shells obtained in this way were compared to structures fabricated by mixing of Turkevich AuNPs with am...

A comparison between Au, TiO2 and self-catalysed growth of SnO2 nanostructures using chemical vapour deposition is reported. TiO2 enables growth of a nanonetwork of SnO2 , whereas self-catalysed growth results in nanoclusters. Using Au catalyst, single-crystalline SnO2 nanowire trees can be grown in a one-step process. Two types of trees are identified that differ in size, presence of a catalyt...

The local reactivity of thin pseudomorphic Pd overlayers on Au(111) and (100) single crystal surfaces has been studied by periodic density functional theory calculations within the generalized gradient approximation. We have determined the adsorption energies of atomic hydrogen and of CO as a microscopic probe of the reactivity. We demonstrate that both surface strain effects and substrate inte...