氮掺杂木质素基活性炭的制备、表征及其吸附性能研究  

Preparation,Characterization and Adsorption Properties of Nitrogen-doped Lignin-based Activated Carbon

作　　者：叶结旺[1] 周志丹 金贞福[1] YE Jiewang;ZHOU Zhidan;JIN Zhenfu(College of Chemistry and Materials Engineering,Zhejiang Agriculture&Forestry University,National Engineering&Technology Research Center of Wood-based Resources Comprehensive Utilization,Hangzhou 311300,China)

机构地区：[1]浙江农林大学化学与材料工程学院,国家木质资源综合利用工程技术研究中心,浙江杭州311300

出　　处：《林产化学与工业》2023年第1期127-132,共6页Chemistry and Industry of Forest Products

基　　金：国家自然科学基金资助项目(51603189);科技部中日双边合作项目(2016YFE0125800);浙江农林大学科研发展基金项目(2019FR016)。

摘　　要：以碱木质素(AL)作为原料,KOH为活化剂,壳聚糖(CS)为氮源制备氮掺杂木质素基活性炭(N-LAC),采用SEM、XPS和N2吸附-脱附等温线等方法对活性炭的结构进行表征,并考察了N-LAC对甲基橙(MO)和亚甲基蓝(MB)的吸附性能。研究结果表明:N-LAC主要由微孔构成,掺氮增大了木质素基活性炭(LAC)的表面孔隙,在制备条件为KOH与AL质量比2∶1、CS添加量(以碱木质素质量计)30%、活化温度800℃、活化时间2 h时,N-LAC的比表面积为1457.79 m^(2)/g,总孔容为0.789 cm^(3)/g,微孔孔容为0.612 cm^(3)/g,平均孔径为2.165 nm。N-LAC中氮元素主要以吡咯型氮(N-5)和吡啶型氮(N-6)形式存在,氮的掺杂会降低活性炭的石墨化程度。N-LAC吸附MO和MB的吸附动力学结果表明:N-LAC吸附MO符合粒内扩散模型,以表面吸附为主;N-LAC吸附MB符合准二级动力学模型。The introduction of nitrogen functional groups on carbon materials can effectively improve carbon materials for dye adsorption performance.We used alkali lignin(AL)as raw material,KOH as an activator,chitosan(CS)for nitrogen source to prepare nitrogen-doped lignin-based activated carbon(N-LAC),the performance of activated carbon was characterized by SEM,XPS and N2adsorption-desorption experiments.Experimental results show that N-LAC is dominated by micropore,and nitrogen addition increases the surface porosity of activated carbon.When the preparation conditions are KOH to alkali lignin ratio of 2∶1,account for 30%of chitosan(alkali lignin mass fraction ratio),activation temperature of 800℃,and activation time of 2 h,specific surface area is 1457.79 m^(2)/g,total pore volume is 0.789 cm^(3)/g,micropore volume is 0.612 cm^(3)/g,and average pore size is 2.165 nm.Nitrogen is mainly in the forms of pyrrole nitrogen(N-5)and pyridine nitrogen(N-6),and the doping of nitrogen will reduce the graphitization degree of activated carbon.The N-LAC was applied to the adsorption experiments of methyl orange(MO)and methylene blue(MB),and the adsorption kinetics showed that,N-LAC adsorbed MO according to the intra-particle diffusion model,mainly based on surface adsorption;N-LAC adsorbed MB according to the quasi-second-order kinetic model.

关 键 词：木质素 KOH 活性炭 壳聚糖 吸附 

分 类 号：TQ35[化学工程]