Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5360492 | Applied Surface Science | 2010 | 5 Pages |
Abstract
Anatase TiO2 and W doped TiO2 films were fabricated by micro-arc oxidation (MAO) on titanium substrates and their hydrogen sensing properties were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the oxide films and electrochemical impedance spectroscopy (EIS) was applied to investigate the gas sensing mechanism. It is found that the conductivity of TiO2 films varies with the introduction of W dopant. EIS analysis reveals that the grains and especially the grain boundaries are mainly contributed to the hydrogen response and their equivalent circuits could be represented electrochemically by parallel resistor and constant phase element (CPE). The enhanced sensor signal at higher measuring temperature (300 °C) is observed with an optimal doping concentration of W ions (1.81 at.%).
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Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Fujian Ren, Yunhan Ling, Jiayou Feng,