基于三维多孔石墨烯材料的γ射线辐照诱导制备及性能研究

Graphene has recently sparked great excitement in the scientific community given its unique two-dimensional structure and excellent mechanical, electronic, and optical properties and possesses attractive prospects in the field of energy conversion, material enforcement, and electronic devices. In which, it is very important to explore appropriate methods for assembling micro graphene sheets into functional macroscopic graphene-based materials. Our previous work has proved the γ-ray irradiation technique can be effectively used for preparation and modification of graphene-based materials. And, we also studied the macroscopic self-assembly behavior of graphene sheets in aqueous solution by chemical reduction self-assembly method. This project herein is proposed to study the γ-ray irradiation induced chemical structure changes and self-assembly of graphene or its derivatives for preparation of functional macroscopic graphene-based materials, especially investigate the basic mechanism of the γ-ray irradiation induced self-assembly of graphene into three-dimensional porous graphene-based materials with structure analysis methods, including X-ray photoelectron spectroscopy(XPS), X-ray diffraction(XRD), Scanning electron microscope (SEM), Raman spectroscopy and so on. In addition, the relationship of structure and properties of three-dimensional porous graphene materials is also planned to explore by combining structural characterization with properties measurement. The results of this project will provide scientific and experimental basis for the preparation of high quality functional macroscopic graphene-based materials with controlled morphology and modulated performance by irradiation technique. It will be very helpful to promote the application of graphene-based materials in the field of energy, environment and so on.

石墨烯因其独特的二维结构和优异的力学，电学和光学等物化性质引发了广泛的研究兴趣，在能源转换，材料增强和电子器件等领域具有诱人的应用前景。其中，探索利用合适技术方法将微观纳米石墨烯片组装成功能化宏观石墨烯基材料具有非常大的研究空间和应用价值。申请人前期研究已证明γ射线辐照能够有效用于石墨烯基材料的制备及功能修饰，同时也通过化学还原自组装方法研究了石墨烯片层的宏观化自组装行为。本项目拟通过γ射线辐照方法，借助X射线光电子能谱，X射线衍射，扫描电子显微镜，拉曼光谱等物化结构分析方法，研究γ射线辐照诱导石墨烯或石墨烯衍生物自组装制备功能化宏观石墨烯材料的物化结构变化规律，特别是三维多孔石墨烯材料的γ射线辐照诱发自组装机理，并结合样品的相关物化性能测试，探究三维多孔石墨烯材料结构与性能的变化关系，为利用辐照技术制备高品质宏观多孔石墨烯基功能材料及其在能源、环境等领域的应用提供科学依据和实验基础。

1、探索了水/乙二胺体系中，氧化石墨烯在γ射线辐照条件下被还原并自组装的可行性，成功制备出石墨烯气凝胶。扫描电子显微图像表明，石墨烯气凝胶的表面较为光滑平整，内部则粗糙多孔。利用红外光谱、X射线衍射、X射线光电子能谱、热重分析等表征手段，有效地证实了所得石墨烯气凝胶的化学结构、还原程度和热稳定性。.同时，石墨烯气凝胶具备多孔结构、疏水特性和热稳定性，可将其应用于有机溶剂的吸附处理。无论是水面浮油或是水底沉油，石墨烯气凝胶均可对之进行有效地吸附，经蒸馏或燃烧处理后，其可实现循环使用。此外，凭借所搭建的循环吸油装置，石墨烯气凝胶可持续吸附浮油并收集，直至浮油被完全清理干净。整个吸附过程无任何水分被吸收，免却了蒸馏处理的繁琐和能耗，以及燃烧处理的浪费和污染，是一种安全、环保、高效和简便的浮油处理方法。.2、在利用γ射线辐射法成功制备出石墨烯气凝胶的基础上，研究了氧化石墨烯在辐照还原自组装过程中的主要影响因素：乙二胺含量和总吸收剂量。研究结果表明，一定含量的乙二胺和适当的总吸收剂量对于氧化石墨烯的还原和自组装过程至关重要。对不同乙二胺含量和不同总吸收剂量所得石墨烯气凝胶的XPS C1s谱进行详细的分峰拟合分析，推测出了氧化石墨烯在水/乙二胺体系中辐照还原的反应机理。.3、研究证明，异丙醇是一种有效的自由基捕获剂。因此，利用异丙醇替代乙二胺作为自由基捕获剂，分析了在水/异丙醇体系中制备出的石墨烯气凝胶所具有的化学结构。根据实验和分析结果，所得石墨烯气凝胶的孔隙结构更为均一，具有更高的C/O比，即还原程度更高。.4、氧化石墨烯和银离子在异丙醇/水体系中经由γ射线辐照诱导还原自组装成三维蜂窝状结构的石墨烯/银复合气凝胶（GA/Ag）材料。通过XRD，XPS，TGA，SEM，TEM表征揭示了氧化石墨烯和银离子被还原成石墨烯和银纳米颗粒，并且银纳米颗粒均匀的负载在石墨烯蜂窝状多孔结构的石墨烯片层上（粒径分布为30～70 nm）。本研究表明γ射线辐照法是合成三维GA/Ag材料的有效方法。.5、鉴于还原氧化石墨烯/银复合气凝胶具有蜂窝状多孔结构，以及该材料本身具备的特有的性质，可将其应用在碘单质的吸附处理。本研究发现无论是暴露在饱和碘蒸气的氛围中还是碘单质处于不同的溶剂中，该材料都能对碘单质进行有效的吸附。