This article will discuss the gas sensitivity of nano plate shaped tungsten trioxide gas sensor at different concentration of ethanol gas, acetone gas, ammonia gas and formaldehyde gas in terms of temperature-sensitivity. As semiconductor material with good sensitivity to various toxic gases, nanostructured tungsten trioxide can effectively improve the sensitivity and response speed of gas sensors. The gas sensor using nanostructured tungsten trioxide as gas sensitive material can be done to make lower thickness detection of target gas, which can greatly decrease the harm of noxious gas to human health. Therefore, the research of nanostructured WO3 is good to make full use of its good semiconductor property, improve its value in the gas sensing field, and provide better semiconductor material.
1.0 Detection of ethanol gas
According to the temperature sensitivity characteristic of the nano-plate-shaped WO3 gas sensor at different concentration of ethanol gas, it is found that with the increase of ethanol concentration the sensitivity of WO3 gas sensor is greater at the same working temperature. When the working temperature is lower than 200℃, the sensitivity of WO3 gas sensor to ethanol gas is low, and when the gas concentration increases to 1000ppm, the sensitivity is 6.58, with the increase of the working temperature, the sensitivity of WO3 gas sensor to ethanol gas also increases, and the sensitivity increases linearly at 300ppm, 500ppm and 1000ppm gas concentration, however when the concentration is 100ppm, the increasing trend is not obvious. Therefore, the optimal working temperature of nano plate type tungsten trioxide gas sensor is 350℃, and the maximum sensitivity is 25.40 when the concentration of ethanol gas is 1000 ppm.
2.0 Detection of acetone gas
According to the temperature sensitivity characteristic of the nano-plate-shaped WO3 gas sensor at different acetone gas concentration, it shows that with the acetone gas concentration increases the sensitivity of the nano-plate-shaped WO3 gas sensor is greater at the same working temperature. When the working temperature of the component test is 150~300℃, the sensitivity under various concentration increases linearly. When the acetone gas concentration is 1000ppm, the sensitivity increases most significantly. At the best working temperature of 350℃, the response-recovery situation of the gas sensor to acetone gas at different concentration is detected, it can be seen that when the concentration of acetone gas is 500ppm, the shortest response time of the gas sensor is 64s, when the concentration of acetone gas is 300ppm, the shortest recovery time of the gas sensor is 66s.
3.0 Detection of ammonia gas
According to the temperature sensitivity characteristic of the nano-plate-shaped WO3 gas sensor at different ammonia gas concentration, it shows that with the increase of the ammonia gas concentration the sensitivity of the nano-plate-shaped WO3 gas sensor raises accordingly at the same working temperature. When the ammonia gas concentration is 25ppm, the maximum sensitivity value of the gas sensor is 2.81 at the optimal working temperature of 325℃, it shows that the nanoplate WO3 gas sensor is very sensitive to ammonia gas and can be detected at low concentration.
4.0 Detection of formaldehyde gas
According to the temperature sensitivity characteristic of the nano-plate-shaped WO3 gas sensor in different concentration of formaldehyde gas, it shows that with the increase of formaldehyde gas concentration the sensitivity of the nano-plate-shaped WO3 gas sensor also raises accordingly at the same working temperature. The response-recovery time is quite important parameter for the gas sensor, at the best working temperature of 250℃the response-recovery situation of the gas sensor to ammonia gas is detected under different concentration. It can be found that when the the concentration of formaldehyde gas is 800pp, the shortest response time of the gas sensor is 40s, and when the concentration of formaldehyde gas is 600ppm, the shortest recovery time of the gas sensor is 55s.
