The Vo <sub> 2 </ Sub> / Tio <sub> 2 </ Sub> Preparation And Properties Of Complex Functional Materials Research

This thesis researched on the preparation techniques of monoclinic VO₂ powders and decreased its phase transition temperature(T_c).Based on this,VO₂/TiO₂ compound material was synthesed successfully and we studied main properties of the composite.This thesis focused on the following three parts:Firstly,taking NH₄VO₃ and KBH4 as raw materials,VO₂ powders were prepared by liquid precipitation method.The effects of pH value,mole ratio of KBH₄ to NH₄VO₃, calcination tempreture and time to the product were discussed,in order to get the optimal condition for preparing VO₂.Secondly,VO₂ powders doped with W⁶⁺ were prepared by direct doping method,to decrease its phase transition temperature.DSC was used to analyse the relation between T_c and doping amount,and then the optical character around T_c was studied by FTIR with heating equipment.Thirdly,VO₂/TiO₂ compound functional material was prepared by grinding method and sol-gel method.The morphology and structure of the composite were characterized by FTIR,XRD and SEM.Moreover,the phase transition property,optical property and photocatalystic property were discussed.In the end,the potential research aspects were raised.The research results show,VO₂ powders prepared by controlling the preparation condition in liquid are with high purity.The phase transition temperature of VO₂ can be decreased remarkably by doping W⁶⁺,and with the increase of doping amount,the Tc is closer to room temperature,with abrupt changes of optical property around T_c.The VO₂/TiO₂ composite material prepared by sol-gel method exhibits a bright future.