磷酸活化的麻皮活性炭纤维的表面织构及其吸附行为

SURFACE TEXTURE AND ADSORPTION BEHVIORS OF HEMP BAST ACTIVATED CARBON FIBERS ACTIVATED BY PHOSPHORIC ACID

用磷酸活化汉麻韧皮制备了麻皮活性炭纤维,利用扫描电镜(SEM)、低温氮吸附、碘吸附以及亚甲基蓝、酸性蓝9吸附等分析手段,对样品的表面形貌、表面织构及吸附行为进行了表征。结果表明,磷酸活化的麻皮活性炭纤维表面光滑,孔隙结构发达,比表面积达到1 142.4 m^2/g,微孔率达到76.16%,微孔呈0.4～0.8 nm和1.2～2 nm双孔型分布,中孔主要分布在2～3 nm之间。碘和亚甲基蓝的最大吸附量分别为1 460.5 mg/g和325.17 mg/g,均超过了国家标准一级产品的指标。20℃时酸性蓝9在麻皮活性炭纤维上的吸附等温线与Langmuir equation的模拟结果相符。

Hemp bast was used to prepare activated carbon fibers by phosphoric acid activation at different pyrolysis temperatures. The resulting products were characterised by SEM, N2 adsorption at 77 K, iodine adsorption, methylene blue and acid blue 9 dyes adsorption from solution. The results show that the products have a smooth surface and contain rich micropores with the maximum specific surface area and micropores content up to 1 142. 4 m2/g and 76. 91%, respectively. The pore sizes are mainly in the range 0. 4 - 0. 8 nm, 1.2 - 2 nm and 2 - 3 nm. The maximum adsorption amounts of iodine and methylene blue of the products are 1 460. 5 mg/g and 325. 17 mg/g, respectively, so the resulting activated carbon fibers are considered as the first grade products specified in the National Standard. The adsorption equilibrium of acid blue 9 dye on the product activated by phosphoric acid at 450℃ were examined at 20 ℃, the results indicate that the equilibrium datas well fit to the Langmuir equation.