Hydrogenation And Electrochemical Properties Of Carbon Nanospheres And The Transform Under High Temperature And Pressure

Fullerene carbon nanospheres with excellent mechanical properties,good conductivity,chemical stability and unique thermal properties,can be widely used in friction materials,electrode materials,storage materials,super capacitor materials and other fields.It has been shown that the performance of hydrogenated carbon nanospheres can be further improved in some aspects,and the degree of hydrogenation has a decisive influence on the parameters such as morphology and structure.Therefore,it is necessary to study the growth mechanism of hydrogenated carbon nanomaterials and tune the degree of hydrogenation,which has important scientific significance and application value.In this thesi,the first part of the work is to studyt the issues mentioned above by the use of solvothermal method.In the experiment trichloromethane was used as the carbon source and metal K as the reducing agent,the C-H bond and C-Cl bond in chloroform were broken by the strong reduction of metal K at 100 ?.The dissociated-Cl and partial –H radicals form HCl,the remained dangling bonds recombine to form a graphitic sheet,through a series of dechlorinationbond and bonding process,and then form hydrogenated carbon clusters,leading to the formation of nanosized hydrogenated carbon onion-like structure.By controlling reaction time,we can study the synthesized hydrogenated carbon nanospheres in different growth stages.We have carried out careful structural characterization for the synthesized samples,and studied the growth and hydrogenation mechanism of hydrogenated carbon nanospheres by comparative test.The effects of reaction time on the degree of hydrogenation and the crystallinity of the as-grown samples have been revealed,which builds a theoretical foundation for further study of nano carbon materials.Electrochemical supercapacitor is a new type of energy storage device that is different from traditional capacitors and rechargeable batteries,which has the most prominent advantages: short charging and discharging time,high specific power and long life.The carbon nano-onin sphere materials have good electrical conductivity and chemical stability,is the most potential material for the super capacitor electrode material.However,due to the immature synthetic process,carbon nano-onin sphere always has been limited.In this part of work,carbon nano-onions with ultra-high capacitance have been synthesized by a flame combustion method,and the specific capacitance is improved by simple high temperature treatments in the following process.In the experiment,naphthalene was used as the carbon source,and the ashes collected after burning in the air were the original samples.The initial capacitance was 77.4F / g.And then the as-synthesized sample was placed in a tube furnace at different temperatures for calcination.When the temperature reached 450 ?,the specific capacitance of the sample was increased to 181.7F / g,and it was still possible to keep more than 90% of the capacitance capacity after 500 constant current charging and discharging cycles,showing a very high cycle stability characteristics.This kind of carbon nano-onions with such high capacitance which can be easily synthesized by a cheap raw materials via synthetic process,has high potential in practical applications.High temperature and high pressure experimental technology is an important method in the field of material synthesis,especially in the process of artificial synthetic diamond..The carbon nano-onin sphere,as a special carbon material,its research under high temperature and high pressure is very significant to study the structure change mechanism.Furthermore,it can provide a new method for people to explore new carbon materials.In this part of work,we carried out preliminary study for the carbon nanoonin sphere under high temperature and pressure.The onin-like structure has been broken,and turned into nano graphite.