碱/尿素溶解体系制备氮掺杂活性炭及其电化学性能研究

Preparation of Nitrogen-doped Activated Carbon from Alkali/Urea Dissolution System and Its Electrochemical Properties

以杉木屑为原料,三聚氰胺固体废弃物(OAT)为氮源,基于碱/尿素体系溶解纤维素,通过一步热解制备氮掺杂活性炭,并考察活化温度和OAT加入量对活性炭的吸附性能和电化学性能的影响。通过X射线光电子能谱(XPS)和比表面积分析仪分析材料的表面结构和孔结构;采用循环伏安(CV)、恒流充放电(GCD)和交流阻抗(EIS)等测试手段表征其电化学性能。研究结果表明:随着OAT质量分数的增加,活性炭样品得率和吸附性能先增加后减小;OAT的添加有利于提高氮掺杂活性炭的得率、氮含量、吸附性能和电化学性能;炭材料的比表面积及其孔隙结构促进活性炭样品电化学性能的提升。当活化温度900℃,OAT质量分数为15%下,制备的氮掺杂活性炭的得率为34.2%,碘吸附值为1116 mg/g,亚甲基蓝吸附值为165 mg/g,比表面积为1324 m^(2)/g,含氮量3.5%。在6 mol/L KOH电解液中,当电流密度1 A/g时,比电容可达193 F/g。

Nitrogen-doped activated carbon was fabricated by one-step pyrolysis with Chinese fir sawdust as raw material,melamine solid waste(oxhydryl and amino triazine,OAT)as nitrogen-rich source,alkali/urea system as solvent.The effects of activation temperatures and melamine solid waste dosage on adsorption performance and electrochemistry performance of activated carbon were investigated.X-ray photoelectron spectroscopy(XPS)and specific surface area analyzer were used to study the surface structure and pore structure of the material.Cyclicvoltammetry(CV)curves,galvanostatical charge/discharge(GCD)and electrochemical impedance spectroscopy(EIS)were used to test the electrochemical performance of samples.The results showed that with the increase of melamine solid waste content,the yield and adsorption performance of activated carbon samples increased first and then decreased;the addition of melamine solid waste was beneficial to increase the yield,nitrogen content,adsorption performance and electrochemical performance of nitrogen-doped activated carbon.The specific surface area and pore structure of carbon materials affected the electrochemical performance of activated carbon samples.When the activation temperature was 900℃and the melamine solid waste content was 15%,the yield of nitrogen-doped activated carbon was 34.2%,the iodine adsorption value was 1116 mg/g,and the methylene blue adsorption value was 165 mg/g,specific surface area was 1324 m^(2)/g,nitrogen content was 3.5%.In the 6 mol/L KOH electrolyte,the specific capacitance could reach 193 F/g when the current density was 1 A/g.