碳源对溶胶-凝胶法合成碳包覆磷酸钒钠纳米结构的影响

Nanostructure of carbon-coated sodium vanadium phosphate by sol-gel synthesis with different carbon sources

以柠檬酸、葡萄糖、草酸、尿素为单一有机碳源,碳酸钠、偏钒酸钠、磷酸二氢铵为钠源、钒源和磷源,使用溶胶-凝胶法合成了前驱体,再经氮气氛围煅烧制备了碳包覆磷酸钒钠复合材料。利用X射线衍射、动态光散射粒径分析、扫描电镜对材料晶体结构、粒径分布及微观形貌进行了详细表征,并分析研究了不同碳源对磷酸钒钠合成过程的影响。结果表明:以柠檬酸、葡萄糖、草酸为单一碳源均能制备出菱形结构的磷酸钒钠覆碳材料,其中以草酸为碳源合成的磷酸钒钠纯度高,结晶度好,形成的碳层均匀包覆在纳米级的球状磷酸钒钠颗粒的表面,产品平均粒度为220nm,粒径分布均匀。

Carbon coated sodium vanadium phosphate materials were synthesized by using sodium carbonate,sodium metavanadate,ammonium dihydrogen phosphate as the main raw materials,while individually using citric acid,glucose,oxalic acid,urea as single organic carbon source.The crystal structure,particle size and microstructure of the obtained products were characterized by XRD,dynamic light scattering particle size analysis and SEM.The results showed that sodium vanadium phosphate synthesized with oxalic acid as carbon source was of high purity and crystallinity with nanosphere morphology coated with evenly dispersed carbon.The product had average size of 220 nm and narrow size distribution.Therefore,oxalic acid was proven to be a good carbon source for the preparation of carbon coated sodium vanadium phosphate.