Preparation Of High Dispersion Pt/zinc Oxide Nanomaterials And Their Sensing Properties To Triethylamine

Zinc oxide is an important n-type semiconductor material,which has a large forbidden band width(3.37 eV),good electrical and thermal conductivity and a wide range of application prospects in gas sensors.At present,zinc oxide gas sensors still have shortcomings such as high operating temperature and low sensitivity.Therefore,in this project,the Pt-supported three-dimensional ordered macroporous(3DOM)ZnO and the nano-particle ZnO gas sensing materials were prepared respectively.The gas sensing performance of ZnO sensors to triethylamine(TEA)was improved through morphology control and composition modification.The composition and structure of the materials were analyzed to explain the gas-sensing mechanism.The specific research content is as follows:1.The 3 DOM ZnO nanomaterials were prepared by the colloidal crystal template method.The 3DOM Pt/ZnO nanomaterials with different loadings were prepared by the incipient impregnation method.The composition and structure of the materials were analyzed through XRD,SEM,Raman,UV-Vis,XPS,CO-DRIFTS and other technologies.The gas sensitivity of 3DOM Pt/ZnO to TEA gas was studied.The results show that a proper amount of loading improved the dispersion of Pt on the surface of the ZnO carriers and the chemically adsorbed oxygen content of the Pt/ZnO gas-sensitive material and reduced the energy barrier of the gas-sensitive reaction,which increased the response of the materials.Compared with the 0.2wt%Pt/ZnO and the 1wt%Pt/ZnO,the 0.5wt%Pt/ZnO material had higher gas sensitivity response,lower detection limit and good selectivity to TEA gas.Under the optimal operating temperature of 150?,the response value to 20 ppm TEA is?441,which is 11 times that of the pure 3DOM ZnO.The sensitivity is 20.7749 ppm-1 and the detection limit is 0.21 ppb.Compared with the reviews,the 3DOM Pt/ZnO had higher gas sensitivity response,lower working temperature and better selectivity,which is expected to be applied in the actual detection of TEA.2.The Pt/ZnO nanoparticles were prepared by electrostatic adsorption method.Due to the difference in carrier morphology,the response value of the 1wt%Pt/ZnO sample to 20 ppm TEA gas at the optimal working temperature of 175? is?410.While the response value of 0.5wt%Pt/ZnO nanoparticles to 20 ppm TEA gas is only?130.