Mn₃O₄/三维多孔石墨烯复合材料的制备

Preparation of Trimanganese Tetraoxide/Three Dimensional Porous Graphene Composites

石墨烯是碳原子以sp2杂化轨道组成的二维纳米材料,由于其具有许多优异的性能而引起人们的极大研究兴趣。本文使用改进的Hummers法制备氧化石墨烯(GO),并利用聚苯乙烯(PS)为牺牲模板,获得三维多孔石墨烯(3D-PG)。该多孔石墨烯的平均微型孔洞为200~300 nm左右,这种微孔洞结构减少了石墨烯特有的堆叠与自团聚特性,也有助于吸附氧化物纳米颗粒。当把这种多孔石墨烯薄膜浸泡在KMnO4溶液中,再通过水热法制备得到Mn3O4/石墨烯复合材料。实验发现,复合材料的形貌与水热时间有很大关系,当水热温度为180℃,水热时间为20分钟时,Mn3O4呈均匀的纳米颗粒,匀和地涂布在孔洞表面。Mn3O4/三维多孔石墨烯复合材料具有的独特三维孔洞结构,既能高负载Mn3O4纳米材料,又有助于提高复合材料的比表面积,有望称为新一代的锂离子电池的负极材料。

Graphene is a two-dimensional nanomaterials composed of carbon atoms with sp2 hybridized orbitals, which has attracted a lot of interest due to its many excellent properties. In this paper, we used improved Hummers method to prepare graphene oxide (GO), and use polystyrene (PS) as a tem-plate to obtain three dimensional porous graphene network (3D-PG). The average micropore size of the porous graphene is around 200 - 300 nm. This kind of porous graphene network reduces graphene’s unique stacking and self-agglomeration, and also helps to adsorb oxide nanoparticles. The Mn3O4/3D-PG composite was prepared by soaking the porous graphene film in KMnO4 solution and then a hydrothermal reduction. The experimental results show that the morphology of the compo-sites is greatly influenced by the hydrothermal condition. When the hydrothermal temperature is 180?C and the hydrothermal time is 20 minutes, the surface of 3D-PG network is coated by homo-geneous Mn3O4 nanoparticles. Mn3O4/3D-PG composites with the unique 3D hole structure of PG not only contributes to the high loading of Mn3O4 nanoparticles, but also the increasing of the specific surface area of the composite, which is expected to be as a new generation of lithium ion battery cathode materials.