铜纳米线@石墨烯三维多孔组装体的可控制备、有序化结构调控及性能研究

Copper nanowires (Cu NWs) are considered as an ideal unite to construct the nanoporous metal materials due to their abundant reserve on earth, high surface area and high electrical conductivity. To date, researches on the three-dimensional (3D) Cu NW architectures have been developed, but the easy oxidation of the nano-Cu which leads to the performance degradation, still remains a bottleneck and restricts the architecture’s practical applications. In addition, microstructure ordering of the architectures is of great significance to further improve their mechanical and electrical properties. Therefore, in this project, we will add different polymer into the Cu NW assembly system, and utilize the polymer matrix to grow thin graphene layer uniformly and completely coated on the surface of the Cu NWs, forming unique core-shell structures. So antioxidative, ultralight and freestanding 3D porous Cu NW@graphene architectures are obtained, and simultaneously the influence of different growth conditions on the graphene shell (including layer number, thickness and doped structure) is illuminated. Then an ice templating method is applied to achieve the orientated and parallel pore pathways in the architectures. We will also reveal the relationship among assembly condition, pore structure and property of the architectures, and obtain stable 3D ordered porous Cu NW@graphene architectures with high ratio strength, high elasticity and high electrical conductivity. Finally, based on these high-performance architectures, we will explore applications in areas such as energy, electromagnetic interference shielding and so on. The project results will push forward the development and applications of the 3D nanoporous metal materials.

铜纳米线具有储量高、表面积大、高导电等特性，是构建高性能纳米多孔金属材料的理想结构单元。目前，三维铜纳米线组装体的研究已经取得了一定的进展，但纳米铜易氧化导致性能衰减的问题仍是限制其实际应用的瓶颈环节。另外，组装体微观结构的有序调控也对其力学、电学性能的进一步提升具有重要意义。因此，本项目拟将不同有机物引入铜纳米线组装体系，并作为固态碳源生长薄层石墨烯，均匀完整地包裹在铜纳米线表面，形成独特的核壳结构，制备抗氧化的超轻自支撑铜纳米线@石墨烯三维多孔组装体，同时阐明不同生长条件对石墨烯层数、厚度以及掺杂结构的影响。然后采用冰模板法实现组装体孔结构的有序化调控，揭示组装条件、孔结构和组装体性能之间的关系，获得高比强度、高弹性、高导电的稳定铜纳米线@石墨烯三维有序多孔组装体。最后，探索高性能组装体在能源及电磁屏蔽等领域的应用。本项目的研究成果将推动三维纳米多孔金属材料的发展和应用。

本项目的主要研究内容是将含碳有机物与铜纳米线共组装，均匀可控地生长石墨烯壳层包裹在铜纳米线表面，制备高性能的铜纳米线@石墨烯三维多孔组装体，结合冰模板法构建组装体的有序化孔道，优化组装体的结构和性能，并基于高导电、高弹性的稳定组装体探索其应用前景。取得的主要研究成果如下：. (1)以聚乙烯吡咯烷酮为组装有机物，通过调节铜纳米线的起始组装浓度，在铜纳米线表面引入了厚度2.9-3.6nm的石墨烯抗氧化保护层，获得了性能稳定的铜纳米线@石墨烯三维多孔组装体。随着铜纳米线组装浓度的增大，组装体的弹性模量由3kPa提高到106.9kPa，不同应变下的强度也随之大幅提升，组装体的力学性得到了极大改善，组装体的导电率与铜纳米线的组装浓度呈正相关，最大可达170.5S/cm。. (2)以聚苯胺为固态碳源，实现了石墨烯壳层的N、P、S、O元素的掺杂。. (3)利用冰模板法的取向冷冻，构建了铜纳米线@石墨烯三维多孔组装体的有序孔道，实现了组装体的局部有序化结构调控。. (4)探索了铜纳米线@石墨烯三维多孔组装体在锂离子电池电极、压力传感、水污染物处理等方面的应用，获得了驱动电压为0.1V，响应时间低至15.93ms，压力检测范围宽至640Pa-82.26kPa的压阻式压力传感器，经过1000次循环测试后性能仍保持稳定；利用化学刻蚀法去除铜框架，制备了大管腔、大晶格间距及氮氧双原子掺杂的导电三维多孔碳纳米气凝胶，获得了高容量的稳定电极材料；基于其三维多孔和疏水特性，组装体可吸附重量是其自身40-90倍的油或有机溶剂，并表现出较高的染料吸附能力。. 本项目在Carbon, Nano Research等期刊发表论文共计11篇，为三维纳米多孔铜材料的实际应用提供了有效的借鉴和参考价值。