Pd2+ reduction and gasochromic properties of colloidal tungsten oxide nanoparticles synthesized by pulsed laser ablation

Abstract

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 Pd 2+ 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 Pd 2+ ions have been reduced. Hence, the gasochromic response for this sample is nearly reversible in all cycles, N. Tahmasebi Garavand · S.M. Mahdavi ( ) · A. Iraji zad

Gasochromic WO3 Nanostructures for the Detection of Hydrogen Gas: An Overview

“…In an interesting study, Garavand et al [99] investigated the gasochromic properties of colloidal WO 3 NPs synthesized by a PLD technique in deionized water using a laser (λ = 1064 nm) at different pulse energies of E 1 = 160, E 2 = 370 and E 3 = 500 mJ/pulse. A PdCl 2 solution was added to colloidal tungsten oxide NPs, after which a laser was used to reduce Pd 2+ to metallic Pd.…”