钒酸钙纳米棒的生长调控及其电化学特性

以乙酸钙和钒酸钠为原料,通过水热过程合成了捆状结构的单晶钒酸钙纳米棒。电镜观察显示所得钒酸钙纳米棒的平均直径约50 nm,长度约3μm。XRD和HRTEM图像显示所得钒酸钙纳米棒由单晶六方Ca10V6O25晶相构成。在钒酸钙纳米棒的生长过程中除了形成六方Ca10V6O25主晶相外,还存在单斜Ca0.17V2O5晶相,随着水热温度和保温时间的增加,单斜Ca0.17V2O5晶相完全转变为了六方Ca10V6O25晶相。采用基于晶体分裂的核化、晶体生长过程可以解释钒酸钙纳米棒的形成与生长。酒石酸在钒酸钙纳米棒修饰玻碳电极上的电化学循环伏安特性曲线中存在一对半可逆的氧化还原电化学伏安特性峰,其检测限为2.4μm,线性范围是0.005~2 mm。

The Growth Control and Electrochemical Properties of the Calcium Vanadate Nanorods

Single crystalline calcium vanadate nanorods with sheaf- shaped structure have been synthesized by a hydrothermal route using calcium acetate and sodium orthovanadate as the raw materials. Electron microscopy observations show that the average diameter and length of the calcium vanadate nanorods are about 50 nm and 3 μm,respectively. XRD and HRTEM observation exhibit that the calcium vanadate nanorods are composed of single crystalline hexagonal Ca10V6O25 phase. The monoclinic Ca0. 17V2O5 phase exists in the calcium vanadate nanorods besides main hexagonal Ca10V6O25 phase. With the increase of the hydrothermal temperature and duration time,monoclinic Ca0.17V2O5 phase totally transforms to hexagonal Ca10V6O25 phase. The formation and growth of the calcium vanadate nanorods can be explained by the nucleation and crystalline growth based on the crystalline splitting process. The electrochemical cyclic voltammogram（ CV） of the tartaric acid at the calcium vanadate nanorods modified glassy carbon electrode shows a pair of semi- reversible oxidation and reduction electrochemical peaks. The calcium vanadate nanorod modified glassy carbon electrode exhibits good performance for the electrochemical detection of tartaric acid with a detection limit of 2. 4 μm and linear range of 0. 005-2 mm.