We report an extensive first-principles investigation of the structure and electronic properties of small Si n (n = 1, 2, 3, 4, and 6) clusters deposited on the Au(111) surface. The calculations were performed using a plane wave based pseudopotential method under the framework of density functional theory. The electron-ion interaction energy has been described using ultrasoft pseudopotentials (USPP) and the spin polarised GGA scheme was used for the exchange correlation energy. The results reveal that Si atom prefers to adsorb on the hcp site of the Au(111) surface with strong binding energy. For Si3, the closed triangle geometry of the bare cluster forms an open triangle by rupturing one of the three Si-Si bonds. Remarkable structural changes in the gas phase geometries were observed from Si4 onwards. For example, while the adsorption of rhombus in parallel and perpendicular orientation to the surface plane remains almost unaltered, the tetrahedral conformation becomes almost flat by the interaction of Au surface. The nature of chemical bonding between Au surface and Si clusters was investigated from the charge distribution analysis and the electronic density of states (EDOS). Based on charge distribution analysis it is found that Si atoms transfer charges to the Au surface. Based on the results it is inferred that Si clusters deposition on the Au surface involves large energy release and would lead to coat the surface by spill over of Si atoms rather than island formation.
- Inderscience Publishers
- Structure and energetics of silicon clusters adsorbed on the ...
Photocatalytic degradation of tartrazine dye using CuO straw-sheaf-like nanostructures
Straw-sheaf-like CuO nanostructures were fruitfully synthesized using a chemical precipitation approach for the photocatalytic degradation assessment of tartrazine. Phase identification, composition, and morphological outlook of prepared CuO nanostructures were established by X-ray diffraction and scanning electron microscopy analysis. The photocatalytic performance of the synthesized CuO nanostructures was appraised in the presence of visible light and the possible intermediates formed during the photocatalytic...
FTIR gas analyzers support management of fire at UK waste facility
The capability to convene a multi-agency Air Quality Cell (AQC) was established in England in 2009 following the Buncefield Oil Storage Depot incident. A review of this event identified the need to rapidly co-ordinate the acquisition, analysis and interpretation of air quality data in major incidents. Arrangements have been made in England to bring together experts from the Environment Agency (EA), Public Health England (PHE) and the UK Meteorological Office on a 24/7, 365 days and year basis to form an AQC for...
Gas analysers support management of Swindon fire
The capability to convene a multi-agency Air Quality Cell (AQC) was established in England in 2009 following the Buncefield Oil Storage Depot incident. A review of this event identified the need to rapidly co-ordinate the acquisition, analysis and interpretation of air quality data in major incidents. Arrangements have been made in England to bring together experts from the Environment Agency (EA), Public Health England (PHE) and the Met Office on a 24/7, 365 days and year basis to form an AQC for any major...
Prepare now for the carbon tax bill or face hefty fines
To avoid massive financial penalties, South Africa-based industries need to immediately prepare for the implementation of the Carbon Tax Bill, warns Roger Rusch, CEO of IWC (Industrial Water Cooling). In November 2015, the National Treasury published the Draft Carbon Tax Bill for public comment. Once implemented, the Bill will penalise companies with excessive Green House Gas (GHG) emissions, with the aim of changing the behaviour of companies by motivating them to shift towards cleaner, more energy-efficient...
Ion Mobility Mass Spectrometry – Catch the Excitement!
Interest in ion mobility mass spectrometry (IMS) technology is growing rapidly. The signs are everywhere. Since the year 2000, the number of abstracts submitted to ASMS mentioning ion mobility has grown more than 10-fold – from 30 to more than 350 in 2015. For most of that time, ion mobility has been available commercially in high-end research instruments or in homemade platforms. Waters changed that with the introduction of the Vion IMS QTof mass spectrometer. With ion mobility now available in a benchtop...