ZnO在不同酸性介质下的水热可控合成

Hydrothermal Controlled Synthesis of ZnO in Different Acidic Media

以乙酸锌为锌源,采取水热合成法制备了ZnO粉体材料。考察草酸、柠檬酸、聚丙烯酸、硫酸铝等不同酸性介质对ZnO形貌及尺寸的影响,并对ZnO晶体的生长机理进行阐述。研究结果表明:草酸根离子、柠檬酸根离子、聚丙烯酸长链、铝离子/偏铝酸根离子等酸性介质对ZnO晶体生长的形貌有着较大影响。在水热温度150℃、反应时间24 h、水热反应起点pH值为12的条件下,草酸根离子的引入有利于ZnO生长成具有较厚片层组成的花状结构,而柠檬酸根离子与偏铝酸根离子则限制了ZnO晶体的纵向生长,起到一个封盖的作用,在柠檬酸根离子作用下ZnO的形貌为双层圆饼状,而在偏铝酸根离子作用下ZnO的形貌转变为薄片。在聚丙烯酸介质下制备的ZnO颗粒粒径为84 nm,在几种酸性介质中粒径最小。研究还发现,上述酸性介质主要通过影响ZnO晶体<2110>、<0110>、<0001>三个方向的相对表面活性和生长速度来控制晶体的生长走向,进而生长出具有不同形貌及尺寸的ZnO晶体。

ZnO powder was prepared by hydrothermal synthesis using zinc acetate as zinc source.The effect of oxalic acid,citric acid,polydactyly acid,aluminum sulfate and other acidic media on the morphology and size of ZnO was studied.The results showed that oxalate ion,citrate ion,polydactyly acid long chain,aluminum ion/metaaluminate ion and other acidic media had great influence on the morphology of ZnO crystal growth.Under the conditions of hydrothermal temperature of 150℃,reaction time for 24 h and initial pH=12,the introduction of oxalic acid ions was conducive to the growth of ZnO into a thick layer of flower structure,and the aluminum citrate ions with partial acid radical ion limited the longitudinal growth of ZnO crystals with capping effect.The morphology of ZnO was double-layer round cake under the effect of citrate ion,and it was thin slices under the effect of metaaluminate ion.The particle size of ZnO prepared in polydactyly acid medium was 84 nm,which was the smallest in several acidic media.It was also found that the acidic medium mainly influenced ZnO crystal orientation<2110>,<0110>,<0001>.The growth trend of the crystals was controlled by the relative surface activity and growth rates of the three directions to synthesize ZnO crystals with different morphologies and sizes.