熔融盐对氧化锆纳米片合成的影响

Effect of Molten Salt on Preparation of Zirconia Nanosheets

以四氯化锆为锆源,乙醇为溶剂,采用溶剂热辅助熔盐法低温煅烧制备氧化锆纳米片。研究并讨论了熔盐种类和用量对氧化锆晶体生长和形貌的影响。结果表明:以NaCl和Na3PO4的混合物为熔盐,且m(前驱体):m(NaCl):m(Na3PO4)=10:10:1时,可以得到平均边长超过1.8μm,厚约70 nm,宽厚比大于10:1的单斜氧化锆纳米片。纳米片为单晶结构,无明显缺陷,主要暴露面为(001)晶面,其在熔盐中的形成符合自聚焦机理,包括溶解、扩散、吸附和生长过程,(001)面主导的氧化锆纳米片与表面能的理论计算结果吻合。

ZrO2 nanosheets were prepared at low temperature by a molten salt method with assistance of solvothermal process using zirconium chloride as zirconium source and ethanol as a solvent.The effects of salt type and content on the growth and morphology of zirconia crystals were investigated.The results show that monoclinic zirconia nanosheets with an average side length of 1.8μm,a thickness of 70 nm and a width:thickness ratio of more than 10:1 can be obtained when NaCl and Na3PO4 are used as composite molten salts and the mass ratio of precursor:NaCl:Na3PO4 is set to 10:10:1.The nanosheet shows single crystal structure with little defects,and the main exposed surface is(001)facet.The formation process in molten salts accords with a self-focusing mechanism,including dissolution,diffusion,adsorption and growth.The large percentage of(001)facet obtained is in reasonable agreement with that based on the theoretical calculation of surface energy.