光致异构分子修饰改性富勒烯复合材料的合成及性能研究

Synthesis and Performance Study of Modified Fullerene Composite by Photo-Isomerization Molecule

摘要:

C₆₀富勒烯为零维碳纳米材料，具有笼状空间结构和优异物化特性（如超导、光催化等），在能源、电子、医药及太阳能等领域中具有极大应用潜力。然而，C₆₀自身特殊的分子结构决定了其本征较差的溶解性和加工性能，限制了其实际应用。因此，高效的表面修饰和表面功能化成为C₆₀复合材料当今的研究热点。针对传统C₆₀复合材料制备方法需要使用有机溶剂、产率不高的现状，提出了一种简便的水相合成法，即通过表面羟基化和自由基加成反应，合成具有光敏特性的偶氮苯分子修饰的富勒烯复合材料AZOC-FC₆₀。利用红外光谱、X射线光电子能谱、紫外可见光谱等技术，对复合材料的结构和光致异构特性进行表征。结果表明，AZOC-FC₆₀复合材料中，AZOC与FC₆₀为共价接枝方式，AZOC分子的功能密度约为1∶41（即每41个C原子接枝1个AZOC分子），使AZOC-FC₆₀复合材料具有较高的功能密度。AZOC-FC₆₀复合材料的结构与FC₆₀类似，为球状团聚结构，但其表面凹凸不平，这是由于AZOC接枝在FC₆₀表面所导致。通过增强分子间相互作用，提高了AZOC-FC₆₀复合材料的光响应特性和结构稳定性，使其回复半衰期提高了4个数量级。综上研究，开发了一种工艺简便的富勒烯复合材料的水相合成法，极大拓展了该复合材料在光热存储/光催化等领域中的应用潜力。

Abstract:

Fullerenes are zero-dimensional carbon nanomaterials with cage-like spatial structure and excellent physicochemical properties， especially the extraordinary physical and chemical properties（such as superconductivity， photocatalysis） exhibited by C₆₀ fullerenes. Fullerene-based composites have been widely used in energy， electronics， medicine， solar energy and other fields. However， the special molecular structure of C₆₀ makes its solubility and processing property poor， thus limiting its practical application. Therefore， to achieve efficient surface modification and functionalization is the focus of research on C₆₀-based nanocomposites. However， due to the limited solubility and processing properties of fullerenes， the traditional preparation methods of fullerene-based composites require organic solvents and the yield is not high. Therefore， a simple aqueous synthesis strategy is proposed. The photoisomerized fullerene composite （AZOC-FC₆₀） was successfully synthesized by surface hydroxylation and free radical addition reaction of fullerene. At the same time， the structure and photoisomerism of the composites were characterized by FT-IR， XPS and UV-vis spectroscopy. The results show that the functional density of AZOC molecule in AZOC-FC₆₀ is about 1∶41， which is equivalent to one AZOC molecule grafted on every 41 C atoms， showing a high functional density. the structure of AZOC-FC₆₀ composite is similar to that of FC₆₀， but its surface is uneven caused by the grafting of AZOC on the surface of FC₆₀； the photoresponse and structural stability of AZOC-FC₆₀ composite are improved by 4 orders of magnitude through enhanced intermolecular interaction. The aqueous synthesis process of AZOC-FC₆₀ composite is simple， which greatly expands the application potential of the composites in the fields of photothermal storage/photocatalysis.