为探究浸渍工艺对活性炭理化性质及性能的影响,以脱除木质素的竹纤维为原料,氯化锌为活化剂,通过真空浸渍、常温搅拌浸渍、物理混合浸渍3种不同的方式浸渍竹纤维,采用化学活化法制备竹纤维基活性炭。通过比表面积及孔径分析仪、傅里叶变换红外光谱仪、X射线衍射仪等对活性炭的孔隙结构、化学结构和晶体结构进行表征,并探讨不同浸渍方式制备的活性炭对亚甲基蓝的吸附能力及电化学性能。结果表明:常温搅拌浸渍制备的活性炭比表面积最大,为2096.981m²/g,物理混合浸渍制备的活性炭比表面积最小,为1788.566m²/g;常温搅拌浸渍制备的活性炭微孔最多,真空浸渍制备的活性炭中孔最多;竹纤维活化后纤维素及半纤维素基本分解,不同浸渍方式制备的活性炭官能团并无显著差异;活化后纤维晶型遭到破坏形成无序炭结构,3种浸渍方式制备的活性炭均具有部分石墨和无序石墨的特征。电化学性能测试表明:3种活性炭均表现出明显的双电层电容特性及可逆性;不同电流密度条件下搅拌浸渍制备的活性炭比电容均最高,电流密度为0.2A/g时比电容达到257F/g;真空浸渍制备的活性炭电荷转移电阻更低,物理混合浸渍制备的活性炭具有更好的导电性;真空浸渍制备的活性炭对亚甲基蓝的吸附能力最好,对亚甲基蓝的平均吸附量为841.5mg/g,物理混合浸渍制备的活性炭吸附性最差。

In order to investigate the influence of impregnation process on the physicochemical properties and performance of activated carbon,delignified bamboo fibers were used as raw material,with zinc chloride as activator,impregnated in three different ways,vacuum impregnation,stirring impregnation at ambient temperature and physical mixing impregnation,to prepare bamboo fiber-based activated carbon by chemical activation method.The pore,chemical,and crystal structures of the activated carbon were analyzed by specific surface area and pore size analyzer,Fourier transforms infrared spectrometer and X-ray diffraction diffractometer,and the adsorption capacity for methylene blue and electrochemical properties of the activated carbons prepared by different impregnation methods were investigated.The results showed that the specific surface area of activated carbon prepared by stirring impregnation at room temperature was the largest,2096.981m²/g,and that of activated carbon prepared by physical mixing impregnation was the smallest,1788.566m²/g.The activated carbon prepared by stirring at room temperature had the largest number of micropores,and activated carbon prepared by vacuum impregnation had the largest number of mesopores.After activation,cellulose and hemicellulose were basically decomposed,and the activated carbon prepared by different impregnating methods did not have significant functional groups.After activation,cellulose and hemicellulose are basically decomposed,and the functional groups of activated carbons prepared by different impregnation methods didn't have significant differences,the crystalline pattern of fiber was destroyed to form disordered carbon structure,and the activated carbons prepared by the three impregnation methods had the characteristics of partial graphite and disordered graphite.The electrochemical performance tests revealed that the three kinds of activated carbons exhibited obvious bilayer capacitance and reversibility.The specific capacitance of activated carbons prepared by stirring impregnation was the highest at different current densities,and the specific capacitance of activated carbon with a current density of 0.2A/g reached 257F/g.The charge transfer resistance of the activated carbon prepared by vacuum impregnation was lower,and the activated carbons prepared by physical mixing impregnation had a better conductivity.The activated carbon prepared by vacuum impregnation had the best adsorption capacity for methylene blue,with an average adsorption amount of 841.5mg/g,and the activated carbon prepared by physical mixed impregnation had the worst adsorption capacity.