棒状LiZnPO4的低温合成与表征

LiZnPO₄的性能与其形貌密切相关,其合成常用的固相法和水热法均无控制其微观形貌的优势。 本文采用改进的沉淀法成功合成了具有棒状结构的LiZnPO₄。 利用热重-差热分析仪(TG-DSC)、X射线衍射仪(XRD)、傅里叶变换红外光谱(FTIR)以及场发射扫描电子显微镜(FE-SEM)等技术研究了LiZnPO₄形成过程、晶相组成、微观结构和形貌。 同时探究了合成方法、煅烧温度、煅烧时间、酸的种类对LiZnPO₄形貌的影响。 结果表明,相比较于固相法,以醋酸为原料的改进沉淀法不仅可以有效降低LiZnPO₄的合成温度至500 ℃,而且很容易控制棒状LiZnPO₄的形成。 在600 ℃下煅烧2 h后可以获得分散性良好、横截面为矩形、直径约为2 μm的规则棒状LiZnPO₄。 此外,对比颗粒状LiZnPO₄和棒状LiZnPO₄的光响应能力,发现棒状LiZnPO₄的光响应能力明显增强。

Low Temperature Synthesis and Characterization of Rod-Shaped LiZnPO4

The properties of LiZnPO₄ are closely related to its morphology. The solid state method and the hydrothermal method are widely used for synthesis of LiZnPO₄, neither has the advantage of controlling the morphology of LiZnPO₄. In this paper, the rod-shaped LiZnPO₄ was successfully synthesized by the modified precipitation method. The forming process, phases, microstructure and morphology of LiZnPO₄ were investigated by thermogravimetry coupled with differential scanning calorimetry(TG-DSC), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR) and field emission scanning electron microscopy(FE-SEM). The effects of synthesis methods, calcination temperature and time, acid types on the morphology of LiZnPO₄ were also explored. The results show that, compared with the solid state method, the modified precipitation method with acetic acid can not only effectively reduce the synthesis temperature of LiZnPO₄ to 500 ℃, but also easily control the formation of rod-shaped LiZnPO₄. LiZnPO₄ can be obtained at 600 ℃ for 2 h by the modified precipitation method with acetic acid, which is regular in rod shape with good dispersibility, rectangular cross section and diameter of about 2 μm. In addition, it was found that the light response capacity of the rod-shaped LiZnPO₄ was significantly enhanced compared with that of the LiZnPO₄ particles without regular morphology.