Abstract Nacre-like composite is promising to realize the intriguing properties of graphene in metal matrix. However, how to fabricate the composite with nacre-like structure and improve effectively its property is still challenging. Here we report a facile synthesis of reduced graphene oxide(RGO)/copper(Cu) composite with hierarchical layered structure based on molecular level mixing and self-assembly. The effects of pH value, temperature, mixing method and graphene content on the microstructure and mechanical property of composite were investigated. The pH value and temperature are the main factors in the formation of hierarchical layered structure. For macroscale microstructure, the composites consist of parallel carbon-rich strip aggregates and carbon-poor matrix. For microscale microstructure, the carbon-rich aggregate contains many micro-layered grains composing of alternating layers of graphene and copper, forming a nacre-like composite structure. Furthermore, it is believed that the length-width ratio of macroscopic aggregates related with the mixing method has a significant impact on the mechanical properties of composites. The tensile strength of the 2.5 vol% RGO/Cu composite is as high as 748 MPa. Moreover, good electrical conductivity is also obtained in the composites. This work provides a better understanding of design graphene based composites with hierarchical layered structure and high performance.

中文翻译：

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超高抗拉强度石墨烯/铜复合材料分层层状结构的制备机理

摘要 类珍珠层复合材料有望实现石墨烯在金属基体中的有趣特性。然而，如何制备具有类珍珠层结构的复合材料并有效提高其性能仍然具有挑战性。在这里，我们报告了一种基于分子级混合和自组装的具有分层分层结构的还原氧化石墨烯（RGO）/铜（Cu）复合材料的简便合成。研究了pH值、温度、混合方法和石墨烯含量对复合材料微观结构和力学性能的影响。pH值和温度是形成分层层状结构的主要因素。对于宏观微观结构，复合材料由平行的富碳条状聚集体和贫碳基体组成。对于微观微观结构，富含碳的聚集体包含许多由石墨烯和铜交替层组成的微层状颗粒，形成珍珠层状复合结构。此外，认为与混合方法相关的宏观聚集体的长宽比对复合材料的力学性能有显着影响。2.5 vol% RGO/Cu 复合材料的拉伸强度高达 748 MPa。此外，复合材料还具有良好的导电性。这项工作为设计具有分层分层结构和高性能的基于石墨烯的复合材料提供了更好的理解。认为与混合方法有关的宏观骨料长宽比对复合材料的力学性能有显着影响。2.5 vol% RGO/Cu 复合材料的拉伸强度高达 748 MPa。此外，复合材料还具有良好的导电性。这项工作为设计具有分层分层结构和高性能的基于石墨烯的复合材料提供了更好的理解。认为与混合方法有关的宏观骨料长宽比对复合材料的力学性能有显着影响。2.5 vol% RGO/Cu 复合材料的拉伸强度高达 748 MPa。此外，复合材料还具有良好的导电性。这项工作为设计具有分层分层结构和高性能的基于石墨烯的复合材料提供了更好的理解。