Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Pd Nanoparticles and Thin Films for Room Temperature Hydrogen Sensor | Nanoscale Res Lett 2009 4 1191-1196 DOI S11671-009-9379-6 NANO EXPRESS Pd Nanoparticles and Thin Films for Room Temperature Hydrogen Sensor Rakesh K. Joshi Subramanian Krishnan Mashamichi Yoshimura Ashok Kumar Received 21 May 2009 Accepted 15 June 2009 Published online 1 July 2009 to the authors 2009 Abstract We report the application of palladium nanoparticles and thin films for hydrogen sensor. Electrochemically grown palladium particles with spherical shapes deposited on Si substrate and sputter deposited Pd thin films were used to detect hydrogen at room temperature. Grain size dependence of H2 sensing behavior has been discussed for both types of Pd films. The electrochemically grown Pd nanoparticles were observed to show better hydrogen sensing response than the sputtered palladium thin films. The demonstration of size dependent room temperature H2 sensing paves the ways to fabricate the room temperature metallic and metal-metal oxide semiconductor sensor by tuning the size of metal catalyst in mixed systems. H2 sensing by the Pd nanostructures is attributed to the chemical and electronic sensitization mechanisms. Keywords Palladium Hydrogen sensors R. K. Joshi A. Kumar El Department of Mechanical Engineering University of South Florida 4202 E. Fowler Ave. Tampa FL 33620 USA e-mail akumar@ R. K. Joshi e-mail joshi@ S. Krishnan Clean Energy Research Center University of South Florida 4202 E. Fowler Ave. Tampa FL 33620 USA M. Yoshimura Nano High Tech Research Centre Toyota Technological Institute Hisakata 2-Chome Tempaku-Ku Nagoya 4688511 Japan Introduction Current trend of research in hydrogen sensor technology is dedicated towards the development of room temperature sensors. Various types of sensors have been widely studied and used for sensing the oxidizing and reducing gases 15 . However it has been a difficult task to detect the gases at room temperature even after adding the metal catalyst into the semiconductors. Recently H2
