High responsive Pd decorated low temperature α-MoO3 hydrogen gas sensor

The H(2 )gas adsorption properties, which are the most crucial concept for a gas sensor, of the 2-dimensional (2D) MoS2 are limited compared to its oxide form of 2D alpha-MoO3. On the other hand, it is straightforward to form high surface-to-volume ratio nanostructures with MoS2. In order to get the benefits of the large surface and better H-2 adsorption properties for the H-2 gas sensor, MoS2 film grown by the chemical vapor deposition (CVD) method was converted into MoO3 with a thermal oxidation process at 380 degrees C under oxygen-ambient conditions. The grown MoS2 film has indicated that it is formed from the coalesced MoS2 flakes. An ultra-high response of 3 x 10(6) at a relatively low temperature of 100 degree celsius was achieved for as low as 800 ppm hydrogen concentration. The hydrogen gas sensing mechanism has been discussed in depth using the double injection model, similar to the electrochromic mechanism.