Research And Application Of Gas Sensor Based CuO

With the development of society and the improvement of people’s living standards,environmental problems have become the focus of people’s concern.Among them,atmospheric problems are particularly serious,such as smog,acid rain,greenhouse effect and other problems caused by the emission of pollutants from a large number of factories.Gas sensor is a kind of component which can detect harmful gas,and one of its most important components is gas sensing material.Metal oxide semiconductor material is a type of gas-sensing material.Because of its high sensitivity and fast response recovery speed,it has received general attention from researchers and has become the mainstream direction of gas sensor research.As a kind of metal oxide semiconductor material,CuO is more sensitive to a variety of harmful gases such as ethanol,ammonia,nitrogen dioxide,hydrogen sulfide,etc.,and has also been extensively studied.In this paper,MOF structure CuO samples,rod MOF structure CuO samples and yttrium doped MOF structure CuO samples with different surface morphology were prepared by hydrothermal method and annealing treatment.The gas sensitivity of trimethylamine gas was tested for each sample.Designed and fabricated a physical rod-shaped MOF structure CuO gas sensor,built a data acquisition system,and conducted test experiments to verify its practicability.The main work of this paper is as follows:1.Using Cu Cl₂and Cu（NO₃）₂as copper sources,several CuO samples with MOF structure were prepared by hydrothermal method and annealing treatment.The morphology and structure characteristics were observed and described,and the gas sensing performance of 50 ppm trimethylamine gas taking the test.The results show that the morphology of CuO material with MOF structure has a poor morphology and structure,and the response value for 50 ppm trimethylamine gas reaches the highest value of 2.1 at 120℃,the response time is 2 s,and the recovery time is 14 s.2.Using Cu（NO3）2 as copper source and adding surface catalysts CTAB and Pv P to the raw materials,rod-shaped MOF CuO samples were prepared by hydrothermal method and annealing treatment.The phase composition was analyzed by XRD,and the morphology and structure was observed by SEM.Finally,the sample was used to make a CuO semiconductor gas sensor,and the gas sensing performance of 50 ppm trimethylamine gas was tested.Based on the rod-shaped MOF Cuo,the CuO samples were prepared by doping yttrium ions.SEM was used to observe the morphology and structure,and the gas sensing performance of 50 ppm trimethylamine gas was tested.The experimental results show that the two materials have the highest response to 50 ppm trimethylamine gas at 110℃,which are 3.9 and4.7 respectively,but the recovery performance of the materials is not good at this temperature.At 140℃,the response value to 50 ppm trimethylamine gas is slightly poor,but it has good response and recovery performance.The response time is 9 s and recovery time is 16 s.In addition,the selectivity and stability of the rod like MOF CuO materials were tested,which proved that the rod-shaped MOF CuO materials have good selectivity and stability.3.Through the built data acquisition system,the gas sensor performance test experiment was carried out on different concentrations of trimethylamine gas,the voltage response of the gas sensor was obtained,and the data fitting was carried out.The experimental results show that the trend of the voltage response of the gas sensor is the same as the trend of the sensitivity curve of the rod-shaped MOF structure CuO material,indicating that its practicability is very good.According to the experimental data,the relationship curve between trimethylamine gas concentration and voltage response,response time and recovery time is fitted,which reflects the influence of trimethylamine gas concentration on the gas sensitivity performance of the gas sensor.