Preparation Of The Heteroatom Dual Doped Mesoporous Carbon Materials And Its Electrochemical Performances

Mesoporous carbon materials with large specific surface area, large pore volume and unique organic skeleton have been widely used in various fields, such as adsorption, separation, catalysis, hydrogen storage, fuel cell, lithium ion battery,biology, drug delivery and slow-release, photoelectric. In this paper, the dual heteroatom doped mesoporous carbon materials were prepared and the electrochemical performance of the prepared materiaks were investigated. The XRD,N2 adsorption, TEM, SEM, XPS characterization methods were used to analyze the morphology structure, and elements composite of the prepared materials.(1) The KOH activated sulfur and nitrogen co-doped ordered mesoporous carbon was prepared by using SBA-15 as the template, pyrrole as nitrogen source, sulfuric acid as catalyst and KOH as activation. The structure of prepared materials was characterizated by using XRD, N2 absorption characterization and XPS. The KOH activated sulfur and nitrogen co-doped ordered mesoporous carbon exhibited high specific surface(2056 m2/g) and large pore volume(1.03 cm3/g). Meanwhile, the prepared material displayed excellent supercapacitance perfornace with a specific capacitance of 375 F/g at a density current of 1 A/g, which walue was 1.95 times higher than that of the pristine sulfur and nitrogen co-doped ordered mesoporous carbon.(2) The sulfur and nitrogen co-doped ordered mesoporous carbon materials exhibited excellent adsorption performance for the Ni2+ in waste water. The and collected after adsorption materials after finishing adsorption, then as the electrode material electrochemical properties were tested. The results indicate that the sulfur and nitrogen co-doped ordered mesoporous carbon materials can be used as an efficient adsorbent for the removal of Ni2+ from aqueous solution. The maximum adsorption capacities calculated from Langmuir model were 105.26 mg/g. The pseudo-secondorder kinetic model was found to provide the best correlation of the used experimental data comparedto the pseudo-first order and the adsorption isotherm could be well defined by Langmuir equation. After treatment by the NH3·H2O and calcine, the final production exhibited excellent supercapacitance performance,which specific capacitance can reached 332 F/g at a current density of 0.25A/g.(3) The phosphorus and sulfur co-doped mesoporous carbon(PMC) was synthesized by a nanocasting method of SBA-15 mesoporous silica as hard template and phytic acid as phosphorus and carbon sources. The results of N2adsorption-desorption showed that the specific surface areas and pore volumes of theprepared materials reached 883~2276 m2/g and 1.7~3.95 cm3/g depended on the carbonization temperature, respectively. The doping content of the phosphorus heteroatoms gradually increased with the increasing pyrolysis temperature, and reached 1.88 at.% as the the pyrolysis temperature at 900 ℃. The electrochemcial measurements showed that the specific capacitance of the electrode materials reached250 F/g at a curren density of 0.5 A/g. The specific capacitance of the electrode materials haven’t apparent changed when the current density increased to 10 A/g.These results demonstrate that the material is a promising electrical material.(4) A novel phosphorus and sulfur co-doped mesoporous carbon materials was prepared by using SBA-15 as template, furfuryl alcohol and phytic acid as the source of carbon and phosphorus, concentrated sulfuric acid as catalyst, respectively. The morphology, surface chemical composition and specific surface area of the materials were characterized by X-ray diffraction(XRD), transmission electron microscope(TEM), X-ray photoelectron spectroscopy. The electrochemical properties of the materials were characterized by cyclic voltammetry, constant current charge discharge,and electrochemical impedance spectroscopy methods. The results indicated that the pore volumes and pore size of the prepared materials reached 0.35~1.69 cm3/g and3.26~5.82 nm depended on the carbonization temperature, respectively. The amount of phosphorus heteroatoms gradually increased with the increasing pyrolysis temperature and variated at 0.56~1.06 at.%. The specific capacitance of the prepared materials reached 123.2 F/g at a current density of 1 A/g.