核桃青皮制备高含氧量多孔炭及其对Ni^2+的吸附性能  

Preparation of High Oxygen Porous Carbon from Walnut Peel and Its Adsorption Properties for Ni^2+

作　　者：余健星 余谟鑫[1,2] 蒯乐 朱博文 YU Jianxing;YU Moxin;KUAI Le;ZHU Bowen(School of Chemistry and Chemical Engineering,Anhui University of Technology,Ma'anshan 234000,China;Sinosteel New Materials Co.,Ltd.,Ma'anshan 234000,China)

机构地区：[1]安徽工业大学化学与化工学院,马鞍山243000 [2]中钢天源股份有限公司,马鞍山243000

出　　处：《高等学校化学学报》2020年第11期2464-2472,共9页Chemical Journal of Chinese Universities

基　　金：中国博士后基金(批准号:2019M652173);国家自然科学基金(批准号:51602004)资助.

摘　　要：以核桃青皮为原料,先用水热法制备其炭前驱体,然后以不同的温度活化得到生物质炭(HBCx).采用扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)、氮气吸附-脱附仪(BET)和X射线光电子能谱(XPS)等手段对HBCx进行了表征,并考察其对废水中高浓度和低浓度Ni^2+的吸附性能.SEM和BET表征结果表明,大量的大孔(约2μm)均匀地分布在HBCx上,其具有分级多孔结构,当活化温度为800℃,所得HBC800的比表面积为94 m^2/g,平均孔径为4.07 nm;炭材料表面含氧和含氮官能团丰富,氧含量(摩尔分数)高达21.24%,可与Ni^2+发生离子交换或共沉淀,这些基团有利于吸附过程的进行.所制备的多孔炭对废液中低浓度的Ni^2+去除率接近100%,表现出优异的吸附性能.Langmuir等温模型能很好地描述了HBCx对Ni^2+的吸附过程,为单分子层吸附,HBC800对Ni^2+的最大理论吸附量高达127.39 mg/g.拟二级吸附动力学模型可以更好地反映吸附过程,吸附速率主要由化学吸附所控制.固定床动态吸附结果表明该材料有优异的工业应用前景.The hierarchical biomass carbon(HBCx)was obtained from walnut green peel,which was first prepared by hydrothermal method,and then activated at different temperatures.The as-made HBCx was characterized by SEM,FTIR,BET and XPS,and its application for adsorption of high or low concentration Ni^2+originated from batteries waste water was investigated.The SEM and BET results show that a large number of macropores(about 2μm)are uniformly distributed on HBCx.HBCx has a hierarchical porous structure.When the activation temperature is 800℃,the specific surface area of the obtained HBC800 is 94 m^2/g with the average pore diameter of 4.07 nm.The results of FTIR and XPS show that the surface of carbon materials is rich in oxygen and nitrogen-containing functional groups,and the oxygen content is as high as 21.24%(molar fraction),which can be ion exchanged or co-precipitated with Ni^2+.These groups are beneficial to the adsorption process.The prepared porous carbon has a removal rate of close to 100%for low-concentration Ni2+in the waste liquid,showing excellent adsorption performance.The Langmuir model fits well with the adsorption isotherm of Ni^2+on HBCx,which demonstrated the adsorption is monolayer.The maximum adsorption capacity of Ni^2+on HBC800 is up to 127.39 mg/g.The quasi-second-order kinetic model can describe the adsorption process better.The adsorption rate is mainly controlled by chemical adsorption.Fixed-bed adsorption result shows that the HBCx is a promising material which can be used in industry widely.

关 键 词：核桃青皮 多孔炭 高含氧量 二价镍离子 化学吸附 

分 类 号：O647.3[理学—物理化学]