Fabrication And Supercapacitor Performance Of Ordered Porous Material Of SiC And Carbon

silicon carbides(SiC)have many fascinating properties of excellent chemical and thermal stability,high hardness,outstanding oxidation and corrosion resistance,and low electrical resistivity and thus are promising materials for many applications.Porous SiC has been widely used in catalyst supports,porous ceramics and gas sensors.Most recently,porous SiC has also exhibited its potential in the electrode materials of supercapacitor.However,it still faces considerable difficulties in synthesizing,constructing and tuning pore structure of SiC since their high stiffness and characteristic of covalent bonds between silicon atom and carbon atom.Herein,A ordered porous material constructed by the SiC interfacing with the carbon has been successful synthesized by developing a technical method of combing the silanization of SBA-15,acetylene CVD and magnesiothermic reduction reaction(MRR)technology.The materials were characterized by XRD,SEM,TEM,BET,XPS,GCD and CV.The results are as follows:1.This ordered porous OM-SiC@OMC material is prepared through the technical route of coating carbon layers onto the walls of the silanized SBA-15 template by the CVD of acetylene,producing SiC by the magnesithermic reduction reaction(MRR)occurring at interface of Si O2 and carbon layers and etching the residual Si O2 of pore walls.OM-SiC@OMC contains two types of ordered mesopores,one type is cylindrical mesopores inheriting from SAB-15 with size of 2.0?3.0 nm,the pore wall is composed of carbon phase,the other is hexagonal mesopores of 3.0?4.0 nm in width formed through etching the unreacted Si O₂ of pore walls of SAB-15,the pore wall is composed of SiC phase.The electrode material shows the higher surface areas reach to 757.4 m²/g,it is benefit to the diffusion of electrolyte ions in the electrode material and provide convenient conditions for electrolyte transportation.2.The performance of OM-SiC@OMC used as the electrode material of supercapacitor was tested by electrochemical methods.As electrode materials of supercapacitor in 6 M KOH,OM-SiC@OMC exhibits a good performance with the capacitance of 194.8 F/g and the energy density of 6.76 Wh/kg at 0.2 A/g,the capacitance retention of 97%after 10000 cycles.In order to increase the voltage window of supercapacitors,the ionic liquid EMIMBF₄ is used as the electrolyte.As electrode materials of supercapacitor in EMIMBF₄,OM-SiC@OMC exhibits a good performance with the energy density of 30.17 Wh/kg at the current density of 0.2 A/g and the operating voltage is 3.5 V,the capacitance retention of 97%after 10000 cycles at 5.0 A/g.