Research on gas sensitive properties of synthesized nano SnO2 based on premixed stagnation flame
SnO2 nanoparticles are synthesized by premixed stagnation flame,and their phase and morphology are analyzed.Compared with chemically synthesized SnO2,the particle size of SnO2 synthesized by flame is smaller,only about 53 nm,with narrow particle size distribution and strong dispersion.Two kinds of SnO2 synthesized by the two methods are used to fabricate sensors,response of the two sensors to C2H4 are studied.The results show that the maximum response value of SnO2 synthesized by flame is 5.82 at 500 ×10-6 C2H4,which is more than twice that of chemically synthesized SnO2.The optimum working temperature of SnO2 synthesized by flame is 400 ℃,which is 60 ℃ lower than that of chemically synthesized SnO2.With the increase of C2H4 volume fraction,the response value of SnO2 synthesized by flame increases,and the difference that of chemically synthesized SnO2 becomes larger and larger.The response speed of SnO2 firstly decreases and then increases with the increase of gas volume fraction,and finally reaches a stable value.The response time of SnO2 synthesized by flame is 2～3 s less than that of chemically synthesized SnO2 when reaching the stable value.To explore its response mechanism,improvement of gas sensitivity of SnO2 synthesized by flame mainly due to the reduction of particle size.
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