高等学校化学学报 ›› 2020, Vol. 41 ›› Issue (11): 2464-2472.doi: 10.7503/cjcu20200449

• 物理化学 • 上一篇    下一篇

核桃青皮制备高含氧量多孔炭及其对Ni2+的吸附性能

余健星1, 余谟鑫1,2(), 蒯乐1, 朱博文1   

  1. 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
  • 收稿日期:2020-07-14 出版日期:2020-11-10 发布日期:2020-11-06
  • 通讯作者: 余谟鑫 E-mail:yumoxin2005@aliyun.com
  • 基金资助:
    中国博士后基金(2019M652173);国家自然科学基金(51602004)

Preparation of High Oxygen Porous Carbon from Walnut Peel and Its Adsorption Properties for Ni2+

YU Jianxing1, YU Moxin1,2(), KUAI Le1, ZHU Bowen1   

  1. 1.School of Chemistry and Chemical Engineering,Anhui University of Technology,Ma'anshan 234000,China
    2.Sinosteel New Materials Co. ,Ltd. ,Ma'anshan 234000,China
  • Received:2020-07-14 Online:2020-11-10 Published:2020-11-06
  • Contact: YU Moxin E-mail:yumoxin2005@aliyun.com
  • Supported by:
    Supported by the China Postdoctoral Science Foundation(2019M652173);the National Natural Science Foundation of China(51602004)

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Ni2+的吸附性能. SEM和BET表征结果表明, 大量的大孔(约2 μm)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 m2/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Ni2+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Ni2+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Ni2+的吸附过程, 为单分子层吸附, HBC800对Ni2+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.

关键词: 核桃青皮, 多孔炭, 高含氧量, 二价镍离子, 化学吸附

Abstract:

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 Ni2+ originated from batteries waste water was investigated. The SEM and BET results show that a large number of macropores(about 2 μm) 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 m2/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 Ni2+. 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 Ni2+ on HBCx, which demonstrated the adsorption is monolayer. The maximum adsorption capacity of Ni2+ 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.

Key words: Walnut green peel, Porous carbon, High oxygen content, Ni2+, Chemical adsorption

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