Research On Gas Sensor Based On Semiconductor Metal Oxide Nanomaterials

In social development,it is often accompanied by the emission of polluting gases.These polluting gases can seriously threaten human health and safety.Therefore,the detection of toxic,harmful and combustible gases always concerns people.Semiconductor metal oxide(SMO)has been widely used in gas sensing research because of its low cost,flexible process and large scale application.For defects such as poor selectivity and long response-recovery time,special morphologies and precious metals are usually used to improve the gas sensitivity of the sensor.In this work,WO₃ nanosheets were prepared by chemical synthesis and annealing method,and their gas-sensitive properties to acetone vapor were measured.The results show that the best operating temperature of the nanosheets is 300?and the response value to 100 PPM acetone vapor is above 4.0.The gas-sensitive response time is 10 s,and the recovery time is 15-20 s.The minimum detection concentration can be 10 PPb.And the acetone vapor has a good selectivity.Subsequently,a sensor array based on WO₃ nanowires,WO₃nanosheets,Pt-WO₃ and Pd-WO₃ was synthesized and processed by PCA.The gas array can not only distinguish individual gases(H₂S,CO,H₂,NH₃),but also better discriminate the mixed gases.It has a good application prospect.