writer：Abdelhamid Boudiba, Chao Zhang, Polona Umek, Carla Bittencourt, Rony Snyders, Marie-Georges Olivier,
keywords：WO3, Hydrogen sensors, Metal oxides
source：期刊
specific source：International Journal of Hydrogen Energy
Issue time：2013年
WO₃ loaded with noble metals is well-known to be sensitive to reducing gases and can be used as hydrogen sensor. This paper presents a simple and attractive method concerning the preparation of hydrogen sensors based on Pd-loaded WO₃ nanocomposites with different morphologies. The influences of the morphology of WO₃ and the palladium growth on its surface on the hydrogen sensing performances are studied. WO₃nanospheres, nanowires and nanolamellae were synthesized by different methods starting from the same precursor (H₂WO₄·nH₂O) which has been obtained by acidification of sodium tungstate (Na₂WO₄). The prepared WO₃ nanostructures were modified with the Pd by dispersing them in a PdCl₂ containing solvent using sonication (giving Pd-WO₃ inks). The sensors were prepared by screen-printing thick films (～10 μm) of these inks on alumina substrates fitted with gold electrodes. The response of Pd-loaded WO₃ sensors to hydrogen was checked for the different morphologies at working temperatures ranging from 180 to 240 °C. The sensors prepared from nanolamellae showed the highest response while the nanowires presented the shortest response time to hydrogen.