| Graphene is a two-dimensional(2D)carbon material with only one atom thick(< 1 nm).It has many excellent properties such as high carrier mobility,high thermal conductivity,and excellent mechanical strength.These important properties are closely related to the linear dispersion near the Dirac point.Graphene aerogel(GA)is a new type of three-dimensional(3D)porous nanomaterial composed of a stack of graphene nanosheets.It has the excellent characteristics of graphene,and has the outstanding advantages of low density,stable chemical properties,good thermal stability and high conductivity.It has great application potential in supercapacitor electrodes,heavy metal ion adsorption,detection sensor,oil pollution cleaning,catalyst carriers and various wearable flexible electronic devices.However,the current GA preparation methods are cumbersome,the preparation conditions are harsh,and the preparation cycle is long,resulting in poor performance of the GA actually prepared,which seriously restricts the large-scale practical application of GA.Therefore,it is still a huge challenge to efficiently prepare 3D graphene aerogel materials with excellent properties.Aiming at the above-mentioned problems,the paper is analogous to the architectural structure model,and innovatively proposes a way of combining two-dimensional(2D)graphene materials with onedimensional(1D)materials(silver nanowires,carbon nanotubes),using the synergistic effect between 1D materials and 2D materials.A graphene-based composite aerogel material with large-scale production has been prepared,and carried out in-depth research on its performance.The main research contents are as follows:1.Graphene oxide(GO),a basic raw material,was prepared by the improved Hummers method.The prepared GO nanosheets have the characteristics of large diameter and high oxidation degree.The pure graphene aerogel samples were prepared by ethylenediamineassisted hydrothermal reduction.The structure morphology difference between GA and GO was analyzed by characterization.The complicated and demanding preparation method of graphene aerogel was optimized through experiments,and a more reasonable preparation process of aerogel has been developed.2.A facile fabrication method of 1D silver nanowires interlocked 2D graphene aerogel(Ag NWs @ GA)was designed.Ag NWs @ GA retains the 3D interconnection hierarchical structure of the original aerogel,and the Ag NWs embedded in the pore wall provide effective support and enhancement to the aerogel structure,forming a robust pore wall structure.The preparation process is simple,high in efficiency,and good in repeatability,and is suitable for industrial production.The high pore structure of Ag NWs @ GA could absorb organic solvents up to 81 times its own weight,and the adsorption performance would not significantly decrease in the long cycle test,and could always maintain the integrity of the aerogel structure,solved the problem of poor circulation performance and fragility of graphene-based aerogel in oil pollution cleaning,which has broad application prospects in the environmental field.3.A simple and efficient method for preparing superelastic graphene-based composite aerogels was introduced.The purified carbon nanotubes were added to the precursor graphene oxide solution.After a series of conditions self-assembly and freeze-drying to obtain carbon nanotube cross-linked graphene aerogel(CNTs @ GA).Due to the synergistic effect of CNTs tightly wound on the bent graphene sheets,CNTs @ GA has the characteristics of ultra-high compressibility(up to 90% strain),excellent elastic properties(irreversible deformation after multiple compression cycles is only 3.7%)and high sensitivity.It solved the problem that aerogels could not be ultra-light and high compressibility at the same time,which provided an ideal choice for manufacturing flexible wearable electronic devices for biological signal detection. |
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