氧化钛柱层状钽钼酸的制备及表征

Preparation and Characterization of Titanium Dioxide-pillared Layered Tantalum-molybdenum Acid

以金属氧化物为层间柱子的层柱过渡金属氧化物是一类新型功能材料,其制备及结构研究具有重要意义.以钽钼酸锂为起始层状化合物,钛酸丁酯为钛源,正丙胺为预支撑剂,通过逐步离子交换方式制得钛(IV)多聚阳离子插层的层状钽钼酸盐,经高温焙烧后得到二氧化钛柱层状钽钼酸.采用粉末X射线衍射(XRD)、傅里叶变换红外(FT-IR)和扫描电镜(SEM)等技术对层柱产品及其前驱体的结构和形貌进行表征,并用漫反射紫外-可见(DRUV-Vis)光谱技术测定光吸收性质.结果显示,TiO2柱层状钽钼酸的层间距为1.12nm,其层柱结构能耐受673K的高温.该层柱产品的带隙能为2.41eV,在可见光区具有一定吸收.

The metal oxide-pillared layered transition metal oxides are a class of novel functional materials,and their preparation and structural study are of great significace.In this research,by using layered lithium tantalum molybdate as a starting layered compound,tetrabutyl titanate as a titanium source and n -propylamine as a pre-swelling agent,the titanium(IV) polycation-intercalated layered tantalum molybdate was synthesized through the stepwise ion-exchange way.Upon calcination at a high temperature,the titanium dioxide-pillared layered tantalum-molybdenum acid was obtained.The pillared layered product and its precursors were structurally characterized by powder X-ray diffraction (XRD),Fourier transform infrared (FT-IR) spectra and scanning electron microscopy (SEM).The photo-absorption performance was investigated by means of UV-visible diffuse reflectance (DR-UV-Vis) technique.The results showed that the interlayer distance of the titanium dioxide-pillared layered tantalum-molybdenum acid was 1.12 nm,and the layered structure was still retained at 673 K.The band-gap energy of the titanium dioxide-pillared layered product was 2.41 eV,indicating that the photo-absorption of the pillared layered product could be broadened to visible region.