Synthesis Of Atom-dispersed Platinum/Tin Oxide And Their Sensing Performance In Triethylamine Detection

N-type semiconductor tin oxide(SnO2)has excellent electrical properties and stable chemical properties,which results in a wide application prospect in the field of semiconductor gas sensors.But at present,SnO2 semiconductor gas sensor still has the disadvantages of high working temperature and low sensitivity,which limits its application.In this paper,the physical and chemical properties of SnO2 were improved by adjusting the morphology of SnO2 and loading precious metal Pt,and the gas sensing performance of SnO2 sensor to trimethylamine(TEA)was improved.The details are as follows:1.The precious metal Pt/SnO2 gas sensing materials with different ratios were prepared by using SnO2 nanoparticles as carriers.It is found that the loading of Pt can significantly improve the properties of SnO2 gas sensing materials.0.20%Pt/SnO2 sample has the best gas sensing performance for TEA.At the optimum operating temperature of 220?,the response value to 100 ppm TEA is?268(which is?6.9 times of that without SnO2),and the response time is 19s.Compared with Pt,SnO2 loading with Ru,Rh,Pd and Ag has higher working temperature or lower response value for TEA.2.SnO2 nanomaterials with three-dimensional ordered macroporous structure(3DOM)were prepared by template method,and their gas sensing properties to TEA were improved by Pt loading.The results show that with 3DOM SnO2 as carrier,the gas sensing performance of Pt/SnO2 gas sensing material for TEA is obviously improved,the optimal working temperature of the sensor is reduced to 80?,the response time is shortened to 10s,and the sensor has good selectivity.CO-DRIFTS test results show that Pt on the surface of 0.20%Pt/SnO2 gas sensing material mainly exists in the state of atomic dispersion,forming more active sites,resulting in the response value of?781 to 100 ppm TEA,which is?20 times of that of the granular Pt/SnO2.Due to the uniform permeability,well-organized pore structure and high specific surface area of 3DOM,the dispersion of Pt and the diffusion efficiency of TEA gas in 3DOM are improved,and the Pt/SnO2 with three-dimensional ordered macropore structure has better gas sensing performance.