不同晶型WO·_30.33H_2O的结构及性能  

Structure and Properties of WO·_30.33H_2O Polymorphs

作　　者：胡栋虎[1] 贺蕴秋[1] 李林江[1] 尹婷[1] 季伶俐[1] 李一鸣[1] 

机构地区：[1]同济大学材料科学与工程学院,上海200092

出　　处：《无机化学学报》2011年第1期11-18,共8页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.50672066)资助项目

摘　　要：以Na2WO4.2H2O为主要原料,采用液相法(80℃)和离子交换-水热法(150℃)分别制备了六方WO3.0.33H2O和以正交相为主的混合晶型WO3.0.33H2O。通过对2种晶型WO3.0.33H2O材料进行X射线衍射(XRD)、场发射电子扫描显微镜(FE-SEM)、红外光谱(FTIR)、X射线光电子能谱(XPS)和循环伏安测试,表征了产物的晶相和结构等。正交WO.30.33H2O结构中由于相邻钨氧八面体层的相互位移而形成空隙,六方WO3.0.33H2O结构中没有位移则形成孔道;正交WO3.0.33H2O具有比六方WO3.0.33H2O更短键长的W=O和更负的导带位置。紫外-可见透射光谱研究表明,六方WO.30.33H2O具有更明显的电致变色效应,可能是因为结构中的孔道使H+易扩散使六方WO.30.33H2O更易发生氧化还原反应。光催化性能研究表明,正交WO3.0.33H2O具有更负的导带位置,价带电子跃迁后易于向电子受体转移,抑制了电子和空穴的复合,使得混合晶型WO3.0.33H2O的紫外光光催化能力相对六方WO.30.33H2O更强。Hexagonal WO3·0.33H2O and mixed WO3·0.33H2O（orthorhombic WO3·0.33H2O as the main phase） were synthesized by liquid method（80 ℃） and by ion-exchange and hydrothermal process（150 ℃）,respectively,using Na2WO4·2H2O as the precursor.The samples were characterized by X-ray diffraction（XRD）,Field Emission Scanning Electron Microscopy（FE-SEM）,infrared spectra（FTIR）,X-ray Photoelectron Spectroscopy（XPS） and Cyclic voltommetry.The inter-shifting of adjacent WO6 octahedron layers in orthorhombic WO3·0.33H2O produces voids,but ways appear in hexagonal WO3·0.33H2O for no displacement;Orthorhombic WO3·0.33H2O had shorter W=O and more minus conduction band than hexagonal WO3·0.33H2O.UV-Vis transmittance spectra indicate that more distinct electrochromism of hexagonal WO3·0.33H2O may be responsible for easy H＋ diffusion into the structure and favorable to redox reaction.Photocatalytic property of mixed WO3·0.33H2O is better than hexagonal WO3·0.33H2O,because more minus conduction bands of orthorhombic WO3·0.33H2O are brought about due to easy absorption of electrons from valence band by electron acceptors and recombination restriction of electron-holes.

关 键 词：六方WO3.0.33H2O 正交WO3.0.33H2O 电致变色 光催化 

分 类 号：O643.613[理学—物理化学] TQ132.41[理学—化学]