An ultra-fast response, high sensitivity structure for optical detection of low concentrations of hydrogen gas, comprising: a substrate; a water-doped WO 3 layer coated on the substrate; and a palladium layer coated on the water-doped WO 3 layer.
1. An in-situ water-doped Pd/WO 3 , sensitivity sensor structure for full coloration optical detection of low concentrations of hydrogen gas at an ultra-fast response time within about 1-2 seconds compared to an undoped Pd/WO 3 , sensor, comprising:
a substrate;
an in-situ addition of a water-doped WO 3 —nH 2 O) amorphous layer coated on said substrate by thermal evaporation; and
a palladium layer coated on said water-doped WO 3 —nH 2 O-nH 2 O layer.
2. A method of preparing a water-doped —Pd/WO 3 high sensitivity sensor structure for optical detection of low concentrations of hydrogen gas at an ultra-fast response time compared to a Pd/WO 3 sensor, comprising:
providing a substrate;
depositing an amorphous layer of WO 3 upon said substrate by thermal evaporation while doping the WO 3 with water by in-situ addition; and
depositing a layer of palladium onto the water-doped WO 3 layer.
3. An improved method of optically detecting low concentrations of hydrogen gas at an ultra-fast response time compared to an undoped Pd/Pd/WO 3 sensor comprising:
subjecting a sensor comprising a substrate, a in-situ addition of a water-doped WO 3 —nH 2 O amorphous layer coated on said substrate by thermal evaporation, and a palladium layer coated on said in-situ addition of water-doped Pd/WO 3 —nH 2 O layer to an environment comprising hydrogen to obtain ultra fast full coloration of said sensor as a detection of hydrogen within about 1-2 seconds compared to an undoped Pd/WO 3 sensor.
4. The sensor structure of claim 1 wherein the amount of hydrogen in the environment is about 1%.
5. The sensor structure of claim 1 wherein said substrate is glass.
6. The method of claim 3 wherein the hydrogen environment is about 1%.
7. The method of claim 3 wherein said sensor structure is subjected to the hydrogen environment after storage in ambient air for about a week and full coloration on detection of hydrogen is about 20 seconds.
8. The method of claim 3 wherein said in situ addition of a water-doped Pd/WO 3 sensor is used in combination with a Pd/WO 3 sensor that becomes saturated at about 2% hydrogen levels.