Study On Synthesis And Gas Sensing Property Of One-Dimension Silver Vanadium Oxide Nanomaterials

In recent years,great attention has been focused on one dimentional nanostructured materials due to the excellent physical and chemical properties. Silver vanadium oxide was applied as anode material in primary batteries,electron spin device and the sensitive device because of good electrochemical,magnetic and electronic transport properties.In the present work,silver vanadium oxide nanomaterials were successfully assembled by ultrasonic treatment followed by rheological self-assembling methods using V₂O₅ sol.The products obtained were analyzed by XRD,SEM,TEM,EDS and SAED.The parameters of the reaction and the growing mechanism were discussed.The gas sensing property and mechanism of bulk AgVO₃ nanomaterials and single AgVO₃ nanorod were also studied.The main conclusions are as follows:1.The obtainedβ-AgVO₃ nanomaterials with the length from several to several tens micrometers form bundles of agglomerated smaller filaments with diameters ranging from 100 to 400 nm.This nanostructure is made up of nanorods with the diameters of 40～100nm coated by Ag nanospheres with diameters of several nanometers to 50nm.2.The increases of hydrothermal temperature and time are helpful to formation of one dimensional nanostrcutres,but the microscale lamella structure will be attained because of the weakening of anisotropic growth when the time exceeds certain values.Stirring and ultrasonic treatment can make Ag₂O particles enter the interlayer of V₂O₅ sol easily and uniformly,resulting in the occurrence of reaction in lower temperature.3.The bulk AgVO₃ nanorods obtained have gas sensing property to ethanol gas. The ethanol gas can react with the negatively charged oxygen adsorbates,and release a trapped electrons at the same time.These electrons can reduce the resistance of the gas sensor.4.The single AgVO₃ nanorod has gas sensing property to methane gas under 0.1V, 300℃in Ar atmosphere with low response concentration of 50 ppm.The methane can dissociates to a methyl group and hydrogen,two hydrogen can react with a lattice oxygen on the surface and produce water and an oxygen vacancy.These oxygen vacancies can reduce the resistance.And two methyl group,a hydrogen can react with a lattice oxygen on the surface,which can produce an oxygen vacancy too. It also enhance the conductivity of the nanorods.Moreover,the Ag on the surface of the nanorods could be helpful to the decomposition reaction of CH₄ at low temperature.