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 ...
Environmental monitoring solutions - Total solution for measuring benzene in gasoline – Case Study
EPA rule 40 CFR Parts 59, 80, 85, 86 (Control of Hazardous Air Pollutants From Mobile Sources) is about to reduce allowable emissions of benzene and other mobile source air toxics. It originally went into effect on April 27, 2007, with a recent Final Release on October 8, 2008.On January 1, 2011, the rule limits the benzene content of reformulated gasoline (RFG) and conventional gasoline (CG) to an annual refinery average of 0.62 volume percent (vol%). If you are a refiner or importer, this rule applies to you.On...
Chemical Engineering Magazine: Odor Issues and Solutions for Wastewater Treatment
Today, there has been a dramatic increase in the number of industrial operations that are located within or near small towns and even large cities. When local residents constantly smell these industrial processes – particularly from wastewater treatment — unhappy neighborhoods are generally the result. In addition, many wastewater facilities can no longer produce odors without facing the consequences of either constant complaints, or fines from federal, state and local authorities. In addition to...
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...