稻壳基高比表面积介孔活性炭的制备与表征

Preparation and activation mechanism of rice husk based mesoporous carbon

以稻壳为原料,KOH为活化剂,分炭化和活化两步制备高表面积介孔活性炭。采用比表面积测定仪测定其N2吸附脱附等温线,采用扫描电子显微镜(SEM)、透射电子显微镜(HRTEM)、X射线衍射分析仪(XRD)对活性炭形成过程中的物相变化与显微结构进行了表征。结果表明,氮气保护下,稻壳在420℃温度下炭化4 h,再将KOH与炭化稻壳按质量比3∶1混合均匀后,在750℃活化1 h条件下制备的活性炭平均孔径可达4.54 nm,比表面积高达2 174.09 m2/g,介孔率达到78.57%。

high surface area mesoporous activated carbons was prepared by a combined method of carbonization and activation processes,in which rice hulls were used as carbon source,and KOH was used as activator,respectively. N2 adsorption and desorption isotherms were employed to determine by the specific surface area determinator. X-ray diffraction（ XRD）,scanning electron microscopy（ SEM）,high resolution transmission electron microscopy（ HRTEM） were used to investigate the phase transformation and microstructure in the formation process of activated carbons. The results show that under the protection of nitrogen,after 420℃ carbonization of 4h,KOH and carbonized rice husk mass ratio 3 ∶ 1,the average pore size of 4. 54 nm activated carbons prepared by1 h activation and activation temperature 750℃,the activated carbons with the specific surface area and mesoporous proportion as high as 2 174. 09 m2/ g,and 78. 57%,respectively,were obtained.