预处理工艺对制备Ca_3Co_4O_(9+δ)粉末的影响

胶体前驱物的预处理工艺将影响柠檬酸溶胶-凝胶法化学合成所得Ca3Co4O9+δ粉末的性能。以金属硝酸盐为起始原料,去离子水为溶剂,柠檬酸为络合剂,溶胶-凝胶化学法合成了Ca3Co4O9+δ溶胶。通过煅烧干凝胶前驱体制得了Ca3Co4O9+δ多晶体粉末,通过控制煅烧时间制备了不同粉末颗粒度的Ca3Co4O9+δ粉末。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、选区电子衍射(SAED)、激光粒度分析仪等手段分析了所得粉末。结果表明:所得Ca3Co4O9+δ粉末物相纯净、结晶良好,颗粒呈层片状结构,晶粒度约300 nm,粉末粒径约300 nm~1.5μm。粉末颗粒度均随煅烧时间延长而增大。

Effects of pretreating procedure on preparation of Ca3Co4O9＋δ powder

Pretreating procedures of dry gel affect the properties of Ca3Co4O9＋δ powder synthesized by citrate acid sol-gel method. The Ca3Co4O9＋δ gel is prepared through sol-gel method with deionized water as solvent, citric acid as chelate, and metal nitrates as starting materials. Polycrystalline Ca3 Co4O9 ＋δ powder is prepared via calcining the dry gel, and the Ca3 Co4O9 ＋δ with different grain sizes is prepared by controlling the calcining time. The obtained Ca3Co4O9＋δ powders are analyzed by XRD, SEM, TEM, SAED and Marlvern granularity analysis. The results show that the Ca3Co4O9＋δ powder is single phased composition with good crystalline quality and flat-shaped powder microstructure, the crystal size is about 300 nm, the grain size ranges from 300 nm to 1.5 um, and the grain size increases with increasing the calcining time.