气相阳离子交换法制备CoO纳米棒及其光学性能

Preparation and Optical Properties of CoO Nanorods by Gas-phase Cation Exchange Method

以水热法合成的ZnO纳米棒为模板,采用气相阳离子交换法制备形貌可控、结晶性良好的CoO纳米棒。通过X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、X射线能谱（EDS）和紫外-可见吸收光谱仪（UVvis）对所得产物的物相组成、形貌、化学成分和光学性能进行表征与测试。结果表明,所得产物为立方相CoO纳米棒,直径在100~150 nm之间,具有较宽的紫外-可见光吸收范围,通过计算得其光学带隙为2.70 e V。此外,能谱分析线扫描探讨阳离子交换机理的研究表明,高温促使Co2＋逐步取代Zn2＋,导致ZnO纳米棒完全转变为CoO纳米棒。

Using ZnO nanorods synthesized by hydrothermal method as template, CoO nanorods with controllable morphologies and well crystallized were synthesized by gas-phase cation exchange method. The structure, morphologies, chemical composition and optical properties of the as-prepared CoO nanorods were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, energy dispersive spectrdmeter （EDS） and UV-visible spectroscopy （UV-vis）. The results indicate that the CoO nanorods with cubic structure and the size is 100-150 nm in width. The CoO nanorods have a broad absorption peak in a wide range from UV to visble light and the band gap of is 2.70 eV. In addition, the cation exchange mechanism were investigated using EDS line scanning profiles. The results indicate that cobalt ion gradually replace zinc ion at high temperature, ZnO nanorods are completely converted into CoO nanorods.