Diffusion-controlled H₂ sensors composed of Pd-coated highly porous WO₃ nanocluster films

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• 作者：Meng Zhao ; J.X. Huang ; C.W. Ong
• 关键词：Hydrogen sensor ; Ultrathin ; Porous ; Nanocluster ; Tungsten oxide film
• 刊名：Sensors and Actuators B: Chemical
• 出版年：February, 2014
• 年：2014
• 卷：191
• 期：Complete
• 页码：711-718
• 全文大小：2456 K

文摘

The resistive H₂ sensing properties of palladium-coated highly porous tungsten oxide nanocluster films (Pd/WO₃), with the WO₃ layers having different thicknesses (11.2-153 nm) and electrodes at different positions, were investigated at 80 掳C. The results were interpreted by using a model involving various mechanisms including surface catalytic dissociation of the H₂ and O₂ molecules, spillover and diffusion of the split species on the surface and inside the WO₃ layer respectively, and the interaction between the species. The validity of the model was further examined by investigating the influences of the WO₃ thickness and the electrode position on the H₂ sensing properties. The results of data analysis confirm the important role of the diffusion of the split species in the WO₃ layer. The optimum sensor is characterized by having an ultrathin WO₃ nanocluster film with a thickness 鈮?1 nm, which exhibits a strong sensor response; short response time and recovery time, and stable resistant output during the hydrogenation process.