Preparation Of Molybdenum Oxide Electrochromic Films By The Oxidation Of Two-Dimensional Molybdenum Disulfide

With the development of ecomomy and industrial technology,demand for energy in every walk of life increases rapidly.That how to utilize existing energy resources fully and effectively has become the theme of today.Building energy consumption accounts for more than 33%of total energy consumption according to figures,so energy-efficient building material is becoming investigative and hot spot.For example,electrochromic devices can achieve the purpose of modulating incident light intensity by changing the electric field.Through study the influence of different surfactants,organic solvents and ultrasonic power on MoS₂ stripping,well-dispersed MoS₂ nanomaterials were obtained by ultrasonic-assisted liquid phase exfoliation method.After being centrifuged,dried and heat-treated,the exfoliated products were dissolved into ethanol and spin-coated on glass substrates.Then,the electrochemical performance of products was studied.Through study the influence of different surfactants,organic solvents and pH on the crystal form and morphology of products,the MoO₃ thin film was growth on FTO glasses successfully by solvothermal method and used to assemble electrochromic device.Then,the electrochemical properties of electrochromic device were studied.Complementary electrochromic devices are assembled by the MoO₃ thin film and the PB thin films which prepared on the glass substrate by hydrothermal method,the its electrochromic properties were studied.The results of this paper are as following:?1?Through exfoliating bulk MoS₂ by ultrasonic-assisted liquid phase method,the experimentation explores the influence of different surfactants,organic solvents and ultrasonic power on MoS₂ stripping.Then,the MoS₂ nanotubes are prepared by ultrasound under 600 W ultrasonic power for 2 h and its thickness is around 50-60 nm.The MoS₂nanotubes are spin-coated on glass substrates and then oxidized into MoO₃ thin film after heat treatment.After that,the MoO₃ thin film are used to assemble electrochromic device and the electrochemical properties of electrochromic device were studied.The results indicate that the MoO₃ electrochromic device shows obvious color change and rapid electrical induction.The MoO₃ electrochromic device gets a maximum optical modulation?16.2%?at 580 nm,the coloring response time is 3.0 s,and the bleaching response time is 9.2 s.3.0 s for coloring and9.2 s for bleaching.?2?Through preparing the MoO₃ thin film on FTO glasses by solvothermal method,the experimentation explores the influence of different surfactants,organic solvents and pH on the crystal form and morphology of products.When the surfactant changed from n-methylpyrrolidone?PVP?to sodium cholate,the surface morphology of MoO₃ films was transformed from sheet to rod.The MoO₃ thin film prepared by solvothermal method are used to assemble electrochromic device and the electrochemical properties of electrochromic device were studied.The results show that the MoO₃ electrochromic device gets a maximum optical modulation?23.6%?at 700 nm,the coloring response time is 6.4 s,and the bleaching response time is 15.5 s.?3?The PB thin film was prepared on FTO glassess by hydrothermal method under 120^oC for 2 h.The PB thin film was observed to be spherical under scanning electron microscope and its diameter is about 500 nm.Complementary electrochromic devices are obtained by assembling the MoO₃ thin film and the PB thin films which prepared on the glass substrate by hydrothermal method.Complementary electrochromic devices have two films.In the effect of external electric field,the two films color and fade at the same time.So complementary electrochromic devices have better optical modulation amplitude and faster response time than single electrochromic devices.The results show that the MoO₃/PB complementary electrochromic device gets a maximum optical modulation about 48.7%,the coloring response time is 10 s,and the bleaching response time is 15.9 s.