Preparation Of Glucose - Based And Pollen - Base Spherical Hybrid Porous Carbon Materials And Its Electrochemical Properties

With the explosive growth of the global population,there has been a rapid increase in the demand for energy.Fossil fuels,the over-consumption of these unrenewable resources,led to a series of environmental problems and serious energy shortages.The development of renewable and green energy for future energy storage systems is becoming more and more important.Due to its advantages of renewable,abundant resources,low cost and easy availability,biomass resources have become the excellent precursors for the preparation of multi-functional carbon materials,attracting a great deal of attention from researchers.Biomass porous carbon material has the advantages of high specific surface area,unique structure,good electrical conductivity and high mechanical strength,and is an excellent supercapacitor electrode material.Glucose(C₆H₁₂O₆)is the most widely distributed and most important monosaccharide in nature,which is a polyhydroxy aldehyde.Glucose is the energy source of living cells and metabolic intermediates,it is the main energy supply of biological.So it is an important biomass.Pollen is a male organ of flowering plants.It is a germ cell in the stamen.Its appearance is powdery.Individual pollen grains are ellipsoid,which is a kind of biomass with unique topography in nature.Pollen contains mainly protein,amino acids,fats,carbohydrates,etc.,which have variety of elements?C,H,O,N,S,etc.?.In this paper,two kinds of spherical hybrid porous carbon materials were prepared by hydrothermal carbonization and activation using glucose and pollen as raw materials.The as-prepared porous carbon materials showed excellent electrochemical performance as supercapacitor electrode materials.The specific research contents are as follows:?1?Preparation of sulfur-doped porous carbon nanospheres and its electrochemical properties:glucose was selected as carbon source,sublimation of sulfur was selected as sulfur source.We employed high-temperature hydrothermal and KOH activation method successfully prepared sulfur doped porous carbon nanosphere material with high specific surface area(3357 m² g^-1).The S-NCS-4 display outstanding electrochemical performance including high specific capacitance(405 F g^-1),excellent rate performance,good cycle stability and high energy density.?2?Preparation of rape pollen-based porous carbon sphere materials and their electrochemical properties:rape pollen was selected as carbon source and cupric chloride was selected as activation agent.Employing one-step carbonization method,nitrogen and sulfur co-doped porous carbon spheres material was successfully prepared with high specific surface area 2448 m² g^-1.The RPC display outstanding electrochemical performance including high specific capacitance(390 F g^-1),excellent rate properties,good cycle stability and high energy density.?3?In order to verify the universal applicability of copper chloride activation,starch,alder bark,coconut shell,chitosan,silkworm cocoon,etc.were used as a carbon source to prepare porous carbon via one-step copper chloride activation.A series of porous carbon material with a high specific surface area were prepared sucessfully.The material shows high specific surface area and outstanding electrochemical performance,which proves that copper chloride has an excellent activation effect and has a good universal applicability in the preparation of porous carbon from biomass.In this chapter,we also found two high-performance activators CuBr₂ and CuBr with excellent activation effects.