Feasibility of H2 sensors composed of tungsten oxide nanocluster films》.pdf

i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y 3 8 ( 2 0 1 3 ) 1 5 5 5 9 e 1 5 5 6 6 Available online at journal homepage: /locate/he Feasibility of H2 sensors composed of tungsten oxide nanocluster films Meng Zhao a,b, Jianxing Huang b, Chung-Wo Ong b,* a Research Center for Solid State Physics and Materials, School of Mathematics and Physics, Suzhou University of Science and Technology, Suzhou 215009, PR China b Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China a r t i c l e i n f o a b s t r a c t Article history: The hydrogen (H ) sensing properties, including the sensor response, response time and 2 Received 21 May 2013 recovery time, of different sensor architectures based on tungsten oxide (WO3) were Received in revised form investigated to assess the feasibility of using WO3 in producing practical H2 sensors. Each 10 September 2013 of the different sensor architectures consists of 3 layers. The first layer is a 2.5-nm palla- Accepted 13 September 2013 dium (Pd) layer, which is always deposited onto a highly porous WO3 nanocluster layer. Available online 9 October 2013 The third layer is an Au/Ti electrode layer, which may be constructed in the form of interdigitated electrodes or 5 5 mm2 pad electrodes, which is located either on the top Keywords: surface of the Pd layer or at the bottom of