Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue
Modification of bamboo-based activated carbon using microwave radiation and its effects on the adsorption of methylene blue
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DOI：
10.1016/j.apsusc.2009.12.025
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发表时间：
2010-03-01
影响因子：
6.7
通讯作者：
Abulikemu, Gulizhaer
中科院分区：
文献类型：
--
作者：
Liu, Qing-Song;Zheng, Tong;Abulikemu, Gulizhaer
在N-2气氛下对竹基活性炭进行了微波改性。通过低温氮气吸附、酸碱滴定、零电荷点（pH(pzc)）测定、红外光谱（FTIR）和XPS光谱对改性活性炭进行了表征。改性过程中，表面酸性基团逐渐减少，而表面碱性有所增强，导致pHpzc值升高。利用FTIR和XPS光谱进一步分析了其官能团的种类以及各元素和基团的相对含量。开始时微孔增多，微孔扩展成更大的微孔，导致孔隙体积增大，平均孔径增大。吸附研究表明，改性活性炭对亚甲基蓝的吸附增强主要是由于微孔的扩大。吸附等温线实验结果表明，Langmuir模型和Freundlich模型分别适用于原生活性炭和改性活性炭。动力学研究表明，改性活性炭对亚甲基蓝的吸附速度更快，拟二阶模型对所有活性炭都具有较好的拟合性。(C) 2009 Elsevier B.V.版权所有
Modification of bamboo-based activated carbon was carried out in a microwave oven under N-2 atmosphere. The virgin and modified activated carbons were characterized by means of low temperature N2 adsorption, acid-base titration, point of zero charge ( pH(pzc)) measurement, FTIR and XPS spectra. A gradual decrease in the surface acidic groups was observed during the modification, while the surface basicity was enhanced to some extent, which gave rise to an increase in the pHpzc value. The species of the functional groups and relative content of various elements and groups were given further analysis using FTIR and XPS spectra. An increase in the micropores was found at the start, and the micropores were then extended into larger ones, resulting in an increase in the pore volume and average pore size. Adsorption studies showed enhanced adsorption of methylene blue on the modified activated carbons, caused mainly by the enlargement of the micropores. Adsorption isotherm fittings revealed that Langmuir and Freundlich models were applicable for the virgin and modified activated carbons, respectively. Kinetic studies exhibited faster adsorption rate of methylene blue on the modified activated carbons, and the pseudo-second-order model fitted well for all of the activated carbons. (C) 2009 Elsevier B.V. All rights reserved.