Fullerene Micro/Nanostructures:Controlled Synthesis And Properties

Fullerenes,as an important family of carbon materials,have attracted widespread attentions due to their unique molecular structures and excellent physical and chemical properties.Assembling fullerene molecules into ordered micro/nanostructures with controllable size and morphology can combine the special properties of fullerene monomers and unique dimensional and size effects,and realize the transformation from nano-molecules to macro-materials.Therefore,the controllable synthesis of fullerene micro/nanostructures is of great significance.However,in the process of synthesizing fullerene micro/nanostructures,there are still deficiencies in the understanding of the molecular self-assembly mechanism and the exploration of properties.Therefore,further researches are needed.In this dissertation,a series of novel fullerene-related micro/nanostructures were controllable synthesis using the solution-driven method.On the one hand,it has enriched the types of fullerene-related micro/nanostructures and increased the understanding of the self-assembly process of fullerene molecules.On the other hand,in view of the different morphological dimensions of the micro/nanostructures,we have studied and modified their properties,and expanded the performance researchs of the fullerene micro/nanostructures in the fields of optoelectronics and energy storage and conversion.The main research contents and results are summarized as follows:(1)A large-area one-dimensional ordered fullerene C₆₀ nanoribbon single crystal array is prepared by the solution-driven dip-coating method.By adjusting the experimental conditions,such as solute concentration,environmental temperature and pulling speed,the morphology,the crystal coverage of the substrate surface and the thickness of the final products are systematically studied.Under the conditions of a pulling speed of 0.25 mm min^-1,a solute concentration of 2 mg m L^-1,and an ambient temperature of 20°C,a continuous stripe array with a relatively smooth surface and a large area is obtained.Due to the few structural defects and the high degree of order,the C₆₀ nanoribbon single crystal array has stable,highly sensitive and fast photoresponse characteristics under ultraviolet light irradiation.This research has opened up a new path for the preparation of fullerene ordered array structures and is expected to expand its application in the field of optoelectronic devices.(2)In order to obtain materials with special functions,the fullerene and cobalt porphyrin molecules are assembled together by?-?interaction to form an ordered supramolecular structure.Three xylene isomers are used as good solvents and n-propanol is used as poor solvent to synthesize fullerenes and cobalt porphyrin co-crystals controllably via the liquid-liquid interface precipitation method.The influence of the solution environment on the crystal morphology and size is discussed,and it is revealed that solvent doping is the key to determining the crystal form of the cocrystals.In addition,the supramolecular assembly of C₆₀ and cobalt porphyrin remains stable at a temperature of700°C,which is significantly better than C₆₀ and cobalt porphyrin monomer,and fluorescence quenching occurs due to the electron transfer between the cocrystals,proving their potential application in the field of high temperature resistant electronics.(3)High temperature carbonization treatment in an inert atmosphere of C₆₀ porous micronsheet is used to modify the properties of fullerenes and to obtain two-dimensional mesoporous carbon material.Its application in the energy field is studied.C₆₀ porous micronsheet carbonized at 1000°C have a high specific surface area,hierarchical pores,appropriate degree of graphitization and abundant structural defects,and exhibit excellent electrocatalytic activity of oxygen reduction(E_onset=0.95 V vs.RHE,E_1/2=0.85 V vs.RHE)and capacitance performance(330 F g^-1),as well as a good cycle stability.(4)Based on the liquid-liquid interface precipitation method,mesitylene is used as a good solvent and n-propanol is used as a poor solvent.The volume ratio of the good solvent and the poor solvent and the concentration of C₇₀ are changed to obtain a series of complex,novel,and highly uniform C₇₀ crystals:from perfect cubes,defective hoppers to novel cruciform-pillars.The mesitylene content in the formed crystals has a great influence on the morphological evolution and growth kinetics of C₇₀ crystals.Meanwhile,these C₇₀microcrystals exhibit excellent optical properties,and due to the influence of morphology,defective hoppers exhibit enhanced photoluminescence properties.This study provides a systematic understanding of the morphological evolution of C₇₀ micro/nanostructures under solvent adjustment.(5)Metallofullerene Lu₂@C₈₂ nanorods with controllable morphology were prepared on the liquid-liquid interface.The size and length of the nanorods were determined by changing the volume ratio of the good solvent and the poor solvent and the concentration of the Lu₂@C₈₂ in carbon disulfide solution.Lu₂@C₈₂ nanorods have single-crystal properties,exhibiting extensive and strong absorption in the ultraviolet region to the visible region,and the increase in crystallinity leads to an increase in photoluminescence intensity.Finally,the prepared single Lu₂@C₈₂ nanorod device has excellent photoresponse properties under the irradiation of 365 nm ultraviolet light,and realizes the performance research of the single metallofullerene fullerene micro/nanostructure in the field of photodetectors.