The Fabrication Of Carbon Monoxide Sensor And Study On Its Performance

Carbon monoxide is a colorless, odorless gas, which can be absorbed into the body through breathing and make harmful effects. It will combine hemoglobin and generates carbonyl hemoglobin, so that the oxygen can not be provide to the human body. When the concentration of carbon monoxide down to 667 ppm, it will probably let the half of the hemoglobin in human body transfer to carbonyl hemoglobin. In this situation, coma, death may occur. When the carbonaceous material imperfect combusts, it will generates carbon monoxide. Due to the development of transportation and mining establishments, as well as the fuel consumption of coal and oil, the emission of carbon monoxide increases quickly. So, monitoring of carbon monoxide is important. Development of a carbon monoxide gas sensor with intelligent, micromation, low-cost, high selectivity and stability is imperative. CNT/inorganic material and polymer/CNT sensitive material were deposited on interdigitated electrodes by spraying process as gas sensor to detect CO at room temperature. The main research works were as follows:MWCNT/Pt and SWCNT/Pt composite film gas sensor had be prepared and were used to detect 5 different concentrations of CO(20ppm、40ppm、60ppm、80ppm、10ppm) at room temperature. The microstructures of sensing films were characterized by scanning electron microscope(SEM). The results exhibited that the SWCNT/Pt composite film gas sensor had better sensing properties compared with the MWCNT/Pt composite film gas sensor. Then SWCNT/CuCl composite film gas sensor had be prepared and were used to detect CO at room temperature. The result showed that SWCNT/CuCl composite film gas sensor had better sensing properties compared with pure SWCNT film gas sensor and pure CuCl film gas sensor. The SWCNT/CuCl composite film gas sensor had also performed good selectivity and stability.PANI/SWCNT and PPY/SWCNT composite film gas sensor had be prepared and were used to detect 5 different concentrations of CO(20ppm、40ppm、60ppm、80ppm、10ppm) at room temperature. The microstructures of sensing films were characterized by scanning electron microscope(SEM). The results exhibited that PANI/SWCNT composite film gas sensor had better sensing properties compared with the PPY/SWCNT composite film gas sensor. We also tested the different proportion of sensing film in response to CO based on PANI and SWCNT. The result showed that when the proportion of PANI and SWCNT was 3:1, the sensor made a better sensing properties.