A study group of Anhui Institute of Optics and Fine Mechanics under Hefei Institutes of Physical Science have explored novel H2S sensor with high selectivity of H2S that is a toxic gas. This work was done by FANG Xiaodong and MENG Gang and their research team.
H2S is one of highly toxic gases. Short-term inhalation of high concentration (~500 ppm) H2S may cause death in a very short time. Even low concentration (~5-20 ppm) H2S if long-term exposure is also harmful to eyes, respiratory system and central nerves. According to National Occupational Health Standards (GBZ 2.1-2007) of China, the occupational exposure limit (OELs) of H2S in the workplace is 10 ppm.
The team reported an ultra-high electrical response of the CuAlO2 sensor of from 4600 to 10 ppm H2S and less than 2 to 100 ppm NH3, NO2 and various volatile organic compounds at 160℃, indicating an excellent selectivity.
In addition, the CuAlO2 sensor also showed a fast response characteristic, once the concentration of H2S in the environment was higher than 4 ppm, 3 orders increase of sensor resistance was accompanied within 1 minute, enabling a prompt alarm.
Besides H2S, the researchers developed high sensitivity and selective ammonia sensor based on delafossite AgAlO2 and CuScO2.
These works were financially supported by the projects of International Cooperation and the National Natural Science Foundation of China, etc.
Link to the paper: A novel ammonia gas sensors based on p-type delafossite AgAlO2
Insight into the Humidity Dependent Pseudo-n-Type Response of p-CuScO2 toward Ammonia
Ultrasensitive and selective CuAlO2 sensor toward H2S based on surface sulfuration-desulfuration reaction