29 / 29
Page 64
conferenceseries
.com
Volume 6
Research & Reviews: Journal of Material Sciences
Advanced Materials 2018
September 19-21, 2018
September 19-21, 2018 Tokyo, Japan
22
nd
International Conference on
Advanced Materials and Nanotechnology
Res. Rev. J Mat. Sci. 2018, Volume 6
DOI: 10.4172/2321-6212-C4-024
Room temperature hydrogen sensitivities of Pd nanorings/TiO
2
nanotubes composite structures
Xiongbang Wei, Xiaohui Yang, Tao Wu, Guodong Lv and Hanying Pang
University of Electronic Science and Technology of China, China
A
novel composite hydrogen sensor consisting of Pd nanorings distributed on TiO2 nanotube arrays was fabricated and
evaluated at room temperature. The layer of Pd nanorings was deposited on top surface of the nanotube arrays by using
a direct current (DC) magnetron sputtering method. Effects of the TiO2 nanotube’s diameter size, Pd nanorings’ thickness on
the sensors’ hydrogen response characteristics were investigated. Time dependence of resistance of the Pd nanorings/TNTs
composite structure on various hydrogen concentrations was also carried out and demonstrated good room temperature
hydrogen sensitive characteristics. Microstructure of the sensor was characterized by Scanning Electron Microscope (SEM)
and it showed that the Pd nanoclusters were deposited on the top of TiO2 nanotubes in isolation. Crystalline structure of
composite analyzing was characterized by X-Ray Diffraction (XRD) and it showed that amorphous TiO2 has been converted
into anatase and rutile completely after annealing at 500 °C. The hydrogen sensing characteristic was tested in series of
hydrogen concentration at room temperature and it revealed that the sensor has excellent response performance. Optimized
experiments demonstrated that the hydrogen sensor composed of 25 nm thickness Pd nanorings distributed on the 77 nm
diameter TiO2 nanotube showed a fast response time (3.8 s) and high sensitivity (92.05%) at 0.8 vol% H2. A hydrogen sensitive
characteristic model is proposed and the Pd nanorings' important role in the hydrogen sensitive mechanisms is described. The
hydrogen sensor's excellent hydrogen sensitive characteristic is ascribed to the Pd nanorings' quick and continual formation
and breakage of multiple passages due to absorption and desorption of hydrogen atoms, so that the composite hydrogen
sensors have promising hydrogen sensitivity at room temperature.
weixiongbang@outlook.com