The Preparation And Application Study On Materials Of Nitrogen-doped Ordered Mesoporous Carbon

Supercapacitors is belived as a promsing energy storage device, have recently received much attention owing to their considerable capacitance, large power density, moderate energy density, and longer cycle-life. Ordered mesoporous carbon materials has unique physical and chemical properties, and it has made great application in electrodes materials. The studies shows that heteroatoms(such as N, P, B) can be effectly enhanced the electrochemical performance of the ordered mesoporous carbon. In this papers, in order to improving the electrochemical performance of the ordered mesoporous carbon, we synthesied a series of nitrogen-doped(or nitrogen-phosphorus co-doped) ordered mesoporous carbons. The materials was haracterized by XRD, TEM, SEM, N2adsorption-desorption, XPS, and electrochemical properties were carried out systematically by electrical measurements.(1) The ordered meoporous carbon SNOMC with Ordered2-D hexagonal structure synthesized by sources-amine as precursor and using SBA-15as the template. The XRD、TEM、SEM show that the materials were duplicated sucessfully. The results of N2adsorption-desorption show that the higher surface areas reach863m2g-1～1061m2g-1and pore volumes reached to1.38cm3g-1～1.56cm3g-1of the materials. The spectrum of XPS exhibites that the N of the sample was grapheme-type and pyridine-type states. Owing to introducing the N atoms,which enhanced the eletrochemical performance. The specific capacitance reached to320F g-1at1A g-1density of the SNOMC materials, which is higher than the CMK-3(129F g-1) who not N-doped and shows that the SNOMC materials are a satisfactory materials.(2) The nitrogen-doped ordered meoporous carbon SKNOMC materials who with partily2D hexagonal symmetry structure were synthesized using pyrrole as precursor and KMnO4as oxidant. The characterization results of XRD, TEM and SEM indicate that the material has ordered structure and partically duplicated the pore structure of SBA-15template. The BET surface areas of the SKNOMC samples reached to381m2g-1～606m2g-1and pore volumes reached to0.54cm3g-1～0.68cm3g-1. The spectrum of XPS exhibites that the N heteroatoms was incorporated into the carbon feamework by grapheme-type and pyridine-type species. The electrochemcial measuaements show that the specific capacitance of the electrode materials reached to315F g-1at a current density of1A g-1. These results demonstrate that the material is a promising electrical material.(3) The nitrogen and phosphorus co-doped ordered meoporous carbons KNPOMC which with the3D Cubic-ordered structure were synthesized using pyrrole as precursor and phosphoric acid as phosphorous sources. The characterization results of XRD, TEM and SEM show that the present materials exhibit partically ordered pores structures. And the BET surface areas of the KNPOMC samples reached to388m2g-1～851m2g-1, pore volumes reached to0.589cm3g-1～1.032cm3g-1. The N heteroatoms was incorporated into the carbon feamework mainly by N-O functional groups for KNPOMC-650while by grapheme-type and pyridine-type species for KNPOMC-800and KNPOMC-950, all of the samples who with the C-P-C functional groups. The maximum specific capacitance of the present materials reaches265F g-1at a current density of1A g-1(4) Calcium nitrate Ca(NO3)2aqueous solution was found to be an effective aqueous electrolyte for a supercapacitor using ordered mesoporous carbon as the electrode materials. The supercapacitive behavior of ordered mesoporous carbon CMK-3electrode in Ca(NO3)2aqueous electrolyte was investigated utilizing cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge measurements. CMK-3electrode shows excellent supercapacitive behavior with wide voltage window, high specific gravimetric capacitance and satisfactory electrochemical stability in Ca(NO3)2aqueous electrolyte. The specific gravimetric capacitance of CMK-3electrode in Ca(NO3)2aqueous electrolyte reaches210F g-1at a current density of1Ag-1, which is higher than that in conventional aqueous electrolytes NaNO3and KOH solution about40%and54%, respectively. The high charge density of the electric double layer formed at the interface of the CMK-3electrode and Ca(NO3)2aqueous electrolyte and the pseudo-capacitive effect originating from the oxygen groups on the surface of CMK-3were believed to respond for the excellent supercapacitive behavior of CMK-3electrode in Ca(NO3)2aqueous electrolyte.