Studyon The Ionic Liquidelectrolyte Material Synthesis And Sensing Performance Of CO Electrochemical Sensor

Gas monitoring has become more and more important in climate,energy,human health and safety.With the development of gas monitoring equipment,the requirements for gas sensors are also rising.Not only high analysis accuracy in detecting target gas,but also on-line detection,low cost,smart,mobility are always required.CO is a toxic gas which will make human body organ failure leading to damage the human health.It is very necessary to monitor and control it effectively.At present,the traditional CO electrochemical sensors mostly use sulfuric acid aqueous solution as electrolyte.Even if the sulfuric acid aqueous solution electrolyte has many advantages?such as low price,convenient etc?,but this aqueous solution of sulfuric acid is easy to be evaporated from the sensor inside,resulting a short sensor lifetime and low gas sensing performance.Therefore,CO electrochemical sensors are hard to run normally within the severe environment conditions?such as high temperature and high humidity?.The characteristics of ionic liquids having non-vapor pressure and wide electrochemical window,can efficiently avoid the drawbacks of traditional electrochemical sensor electrolytes.In this paper,we used different ionic liquids as the electrolyte to obtain some CO electrochemical sensors and studied the the structure-activity relationship between different ionic liquid properties,structures and CO sensing performance.First,the 32 kinds of different ionic liquids as electrolyte were investigated to study the gas-sensing performance of CO and the main reasons.The results show that the CO gas sensor using acid ionic liquid as electrolyte exhibit a good linear relationship between 100 ppm and 900 ppm of CO concentration?R²>0.995?,and the response time T₉₀0 of the sensor is between 30 s and 60 s,the recovery time F₉₀0 is within 60 s.Also,the smaller the IL's molecular structure and the stronger the ILs acidity,the better CO sensing performance is obtained.Second,in order to solve the bad repeatability of the CO sensor using only one ionic liquid as electrolyte,the electrolyte mixing two different ionic liquid was prepared.The results showed that the CO sensor using the mixture with two ionic liquid as electrolyte also exhibited a good linear relationship between 50 ppm and600 ppm of CO concentration?R²>0.995?.What's more,the lowest detectable limit to the CO concentration can reach to 10 ppm,and the response time T₉₀0 of the sensor was between 30 s and 50 s.The recovery time F₉₀0 is within 60 s and the repeatability CO sensor using ionic liquid as electrolyte is good.