Loading...

Pd 2+ reduction and gasochromic properties of colloidal tungsten oxide nanoparticles synthesized by pulsed laser ablation

Garavand, N. T ; Sharif University of Technology | 2012

1443 Viewed
  1. Type of Document: Article
  2. DOI: 10.1007/s00339-012-6899-1
  3. Publisher: Springer , 2012
  4. Abstract:
  5. Tungsten oxide nanoparticles were fabricated by a pulsed laser ablation method in deionized water using the first harmonic of a Nd:YAG laser (λ = 1064 nm) at three different laser pulse energies (E1 = 160, E2 = 370 and E3 = 500 mJ/pulse), respectively. The aim is to investigate the effect of laser pulse energy on the size distribution and gasochromic property of colloidal nanoparticles. The products were characterized by dynamic light scattering (DLS), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and UV-Vis spectroscopy. The results indicated that WO 3 nanoparticles were formed. After ablation, a 0.2 g/l PdCl 2 solution was added to activate the solution against hydrogen gas. In this process Pd2+ ions were reduced to deposit fine metallic Pd particles on the surface of tungsten oxide nanoparticles. The gasochromic response was measured by H 2 and O 2 gases bubbling into the produced colloidal Pd-WO 3. The results indicate that the number of unreduced ions (Pd 2+) decreases with increasing laser pulse energy; therefore, for colloidal nanoparticles synthesized at the highest laser pulse energy approximately all Pd2+ ions have been reduced. Hence, the gasochromic response for this sample is nearly reversible in all cycles, whereas those due to other samples are not reversible in the first cycle
  6. Keywords:
  7. 1064 nm ; Colloidal nanoparticles ; First cycle ; First harmonic ; Hydrogen gas ; Laser-pulse energy ; ND : YAG lasers ; Pd particle ; Tungsten oxide ; UV-vis spectroscopy ; Atomic force microscopy ; Colloids ; Deionized water ; Dynamic light scattering ; Hydrogen ; Ions ; Laser ablation ; Laser pulses ; Nanoparticles ; Neodymium lasers ; Oxides ; Photoelectrons ; Tungsten compounds ; Ultraviolet visible spectroscopy ; X ray photoelectron spectroscopy ; Synthesis (chemical)
  8. Source: Applied Physics A: Materials Science and Processing ; Volume 108, Issue 2 , 2012 , Pages 401-407 ; 09478396 (ISSN)
  9. URL: http://link.springer.com/article/10.1007%2Fs00339-012-6899-1