The Preparation And Characterization Of MoO₃and Its Compounds And Li⁺Embedded System

MoO3is one of the metal oxides with good optical properties and electricproperties. It is widely used in various scientific fields, such as gas sensitive material,catalyst, color window, variable reflectivity mirrors, information storage, imagedisplay, etc. It was found that different annealing temperatures on the MoO3filmswhich are prepared by PVD would influence films’ properties. It was also found thatthe structure and electric properties of MoO3films would be influenced ifMoO3/graphene compounds were prepared by hydrothermal method under differentheat temperature.In this paper MoO3were deposited onto indium-tin oxide(ITO) glass substrateby Radio Frequency (RF) magnetron sputtering.MoO3/graphene compounds wereprepared by hydrothermal method. The characterization methods such as transmissionspectra, X-ray diffraction (XRD), cyclic voltammetry (CV), Raman spectra were usedto characterize the samples. On top of this, we studied the electric properties ofMoO3/graphene compounds which were used as cathode materials of lithium battery.The RF magnetron sputtering was used to prepared MoO3films by employingthe metal Mo target. The deposition pressure was5×10-4Pa.The flow of O2and N2respectively were22.5sccm and2.5sccm.The deposition power was100W and thedeposition time is2h.Then these films were heated at different temperature such as100℃、200℃、300℃、400℃. Transmission spectra, cyclic voltammetry and Ramanspectra of these films were studied. It is concluded that when the annealingtemperature were more than200℃, it appeared two anodic and cathodic peaks with lithium ions inserting into MoO3filmsand the reversibility of films got worse. But the charging efficiency and the colorationefficiency of MoO3films got best when the annealing temperature was200℃.Thetransmittance of the colored MoO3films was better when the annealing temperaturewas lower than100℃.MoO3/graphene compounds were prepared by hydrothermal method and themass ratio of MoO3and graphene were different. The heated temperature were120℃、140℃、180℃respectively. We compared XRD, Raman spectra and the electricproperties of different samples. It is concluded that:(1) With the addition of（NH4）6Mo7O24,α-MoO3would turn to h-MoO3and the reduction process of GOwould be stopped if the heated temperature was not changed.(2) When the mass of（NH4）6Mo7O24was same, h-MoO3would be more if the heated temperature gotlower. Conversely, h-MoO3would turn to α-MoO3if the heated temperature gothigher.(3) The first charge and discharge of MoO3/graphene compounds was verygood, so the compounds could be expected to become the ideal material of lithium ionintercalation.(4) When the heated temperature was lower, the first discharge capacityand charge and discharge efficiency were higher. The cyclicity of charge anddischarge was also better.