石墨烯与Ag纳米颗粒复合材料的制备与表征

Preparation and characterization of the composite of graphene and Ag nanoparticle

采用液相混合与水热还原相结合的方法制备了一种颗粒直径在10～ 20 nm之间,分布均匀的石墨烯与Ag纳米颗粒复合材料.利用透射电子显微技术研究在不同反应阶段时石墨烯或氧化石墨烯表面颗粒的晶格结构与组成成分.研究结果表明,在液相混合阶段Ag＋与氧化石墨烯之间发生了氧化还原反应,Ag＋还原成为Ag纳米颗粒并附着于氧化石墨烯的表面,颗粒的直径在5 nm以下,分布均一;在水热还原氧化石墨烯阶段,Ag纳米颗粒发生了奥斯瓦尔德熟化现象,较小的Ag纳米颗粒随着水热反应的进行不断的溶解,并在较大的Ag颗粒表面凝聚,使得颗粒的尺寸增加.

The composite of graphene and Ag nanoparticle was obtained via liquid mixing and hydrothermal method. The Ag nanoparticles＇ diameters range from 10 nm to 20 nm with a uniform distribution. The crystal phase information and chemical composition of this composite at different reaction stages were characterized by transmission electron microscopy. The results indicate that there is a redox reaction between graphene oxide and Ag^＋ during the mixing stage. Ag^＋ is reduced to be Ag, and then attached to the surface of graphene. The Ag nanoparticles＇ diameter is smaller than 5 nm with a uniform distribution. The diameters of Ag nanoparticles increase due to a consequence of Oswald ripening during the bydrothermal reduction.