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Colouration process of colloidal tungsten oxide nanoparticles in the presence of hydrogen gas

Tahmasebi Garavand, N ; Sharif University of Technology | 2012

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  1. Type of Document: Article
  2. DOI: 10.1016/j.apsusc.2012.06.081
  3. Publisher: Elsevier , 2012
  4. Abstract:
  5. In this study, tungsten oxide nanoparticles were fabricated by pulsed laser ablation (PLA) of tungsten target using the first harmonic of a Nd:YAG laser (1064 nm) in deionized water. After ablation, a 0.2 g/lit PdCl 2 solution was added to activate the solution against the hydrogen gas. Dynamic light scattering and X-ray photoelectron spectroscopy were used to measure the average size and the surface chemical composition of the synthesized nanoparticles, respectively. The aim is to investigate the influence of hydrogen exposure time on colouration process of colloidal nanoparticles. According to optical measurements, hydrogen bubbling into the produced colloidal Pd-WO 3 led to formation of several absorption peaks at ∼1.26, ∼1.6 and ∼1.97 eV. We observed the appearance and growth of a peak at 1.6 eV at the initial stages of hydrogen exposure. However, two other peaks became dominant at long exposure times. The coloration process is reversible in the presence of oxygen gas
  6. Keywords:
  7. Optical absorption ; Tungsten oxide nanoparticles ; 1064 nm ; Absorption peaks ; Average size ; Colloidal nanoparticles ; Coloration process ; Exposure time ; First harmonic ; Gasochromic ; Hydrogen exposure ; Hydrogen gas ; Initial stages ; ND: YAG lasers ; Optical measurement ; Oxygen gas ; Pulsed-laser ablation ; Surface chemical composition ; Tungsten oxide ; Deionized water ; Hydrogen ; Laser ablation ; Light absorption ; Nanoparticles ; Neodymium lasers ; Optical data processing ; Oxides ; Photoelectrons ; Tungsten ; Tungsten compounds ; X ray photoelectron spectroscopy ; Synthesis (chemical)
  8. Source: Applied Surface Science ; Volume 258, Issue 24 , 2012 , Pages 10089-10094 ; 01694332 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0169433212011440