Acetone sensing of Au and Pd-decorated WO3 nanorod sensors

The sensing properties of WO3 nanorods decorated with both Pd and Au nanoparticles toward acetone were examined. AuPd-decorated WO3 nanorods were prepared by immersing the WO3 nanorods in an acetone/(25 mM) HAuCl4/(25 mM) PdCl2 solution followed by UV irradiation and annealing. The WO3 nanorods decorated with Au and Pd nanoparticles exhibited a far stronger response to acetone gas that increased with increasing acetone concentration than the monometal-decorated counterparts. XPS analysis showed that considerable alloy formation has occurred during the annealing process of the Au and Pd nanoparticle-decorated WO3 nanorods. Overall, Au and Pd particle-decoration had a synergistic effect on enhancing the sensitivity of the WO3 nanorod sensor to acetone gas. The underlying mechanism of the enhanced response of the Au/Pd bimetallic particle-decorated WO3 nanorods is also discussed.