Transition metal oxides covered Pd film for optical H2 gas detection

We have developed a simple fiber optic Fabry–Perot interferometer (FPI) sensor that is used to detection and measure concentration of hydrogen gas in the air. The operating principle of the sensor is discussed in this paper, and it was noticed that the wavelength positions of the FPI reflectance peaks change with the concentration of hydrogen gas. The sensor has been successfully used to monitor concentration of H2 in the air below Lower Explosion Limit (LEL). The sensor utilizes a layered sensing structure. This structure includes gasochromic titanium dioxide (TiO2) and nickel oxide (NiOx) sensing film. The optical H2 gas sensor has a very short response time and a fast regeneration time at room temperature.