Preparation Of Porous Carbon Material And Electrochemical Enery Srorge Applications

Due to the high specific surface area and considerable electrical conductivity, porous carbons possess huge application potential in surface and conductivity relevant applications such as electrode materials of electrochemical devices and adsorbents in pollution treatment. Especially, in electrode materials of supercapacitors, the high surface areas, hierarchical pore structure, suitable pore size and the conductivity of porous carbons are beneficial for the rapid transfer of charges and electrolyte ions, thus offers high capacitance, rate capability and cycling performance, and therefore the energy and power delivery performances can be improved. In this thesis, several natural feedstocks were mainly employed as precursor for preparation of porous carbons via carbonization and activation treatment, the afforded products were further used as electrode materials of supercapacitors. The main content involves the following aspects:(1) Hierarchically interconnected porous carbon microtubes with proper graphitization degree, high surface area(1012 m2 g-1), incorporated micropores and meso-/macropores were synthesized by carbonization and alkali activation of Plateaus fruit precursor. In this product, efficient charge/ions transfer channel was constructed owing to the co-existance of micro- and meso-/macropores. The supercapacitor electrode based on this porous carbon can offer a high capacitance of 215.38 F g-1, a high rate capability and excellent cycling stability. Moreover, the porous carbon microtubes was used as adsorbent for dye sucking to make full use of its high specific surface area, a 550 mg g-1 dye(MB) adsorptin capacity was achieved. The adsorption isotherms and adsorption kinetics of the dye sucking was systematically investigated, and the relationship between the structure of porous carbon microtubes and surface related application performances were further analyzed.(2) Nitrogen doped graphene-porous carbon composites with the enwrapping architecture was synthesized by carbonization and activation treatment of egg white(hetero-elemental and carbon source) and graphene oxide. The electrochemical charge storage performance of this composite as electrode material of supercapacitor was investigated. Both the incorporation of nitrogen elemental and the formed multi-dimensional channel within graphene and porous carbon are beneficial for enhanced energy storage performance. The as-fabricated supercapacitor offered a high capacitance of 333 F g-1, excellent rate capability and cycling stability. The assembled capacitor groups by connection of individual units in series can still maintain the same capacitance as that in individual units, showing the great potential of this material in electrochemical energy storage.(3) Employing fish scale as precursor, sheet-like porous carbon material with a high graphitization degree was synthesized by carbonization treatment. The electric double layered supercapacitor using the as-prepared porous carbon as electrode material can offer a capacitance approaching to 200 F g-1. On the other hand, carbon quantum dots were also synthesized by hydrothermal treatment of fish scale, the fluorescence quantum yield achieves 0.52. The fluorescence performance can be well maintained in complicate environment containing various metal ions, which benefits the application in fluorescence analysis for its robust anti-interference ability.