Synthesis And Gas Sensing Application Of CuO Doped SnO₂ Hollow Spheres

Gas sensing technology is receiving much more attention in the practical applicationsincluding industrial and academic fields in past decades.Its potential application areas are industrial production,automotive industry,medical application,indoor air quality supervision and environmental monitoring,etc.Thus,various materials such as metal oxide,conjugated polymers and carbon nanomaterials have been explored to fabricate gas sensors.At present,the most widely used is tin oxide?SnO₂?and its composite materials.The gas sensing properties of tin oxide?SnO₂?sensors was being improved these years.The combination of n-type oxides and p-type oxides can significantly improve gas sensing properties.Therefore,copper oxide?Cu O?was combined with tin oxide?SnO₂?to improve the gas sensing properties of tin oxide?SnO₂?material.The material preparation method and morphology are also important factors that could influence the gas sensing properties of materials.In this paper,hollow spheres were prepared by template method to improve the specific surface to area ratio of the material,so as to further improve the sensitivity of the sensor.The gas sensing performance can be tested by static or dynamic test method,this paper used the dynamic test method to obtain the gas sensing properties.By comparing the test results,the sensitivity,optimum working temperature of the sensor,the response/recovery time were obtained.In this paper,a high activity carbon spheres template was prepared by glucose hydrothermal method.The single phase material of Cu O and SnO₂ and five kinds of Cu O-SnO₂ composite with different proportions were prepared by template method.The characterization results show that the prepared materials exhibit hollow sphere characteristics.EDX results showed that the impurity was not introduced during the preparation of the material.Gas sensors were prepared using these materials,and their gas sensing properties were tested.The results showed that gas sensing performance of the Cu O-SnO₂ composite,which origin from the solution that concentration of Cu2+/Sn4+ was 1/100,was better than that of single phase Cu O,SnO₂ and other composite materials have more excellent gas sensitivity.The optimum working temperature is 300?,and the sensitivity of 200 ppm to alcohol vapor at 300? is 24.40.In addition,another kind of P type metal oxide Cr2O3 hollow spheres was prepared by template method,and the TEM test and N2 adsorption and desorption experiments were carried out.Sensors were fabricated to test the gas sensitivity.The gassensing mechanism of the sensor is deeply discussed after the gas sensitivity test results are obtained.