不同预处理方法对活性炭纤维结构和吸附性能的影响

以商品活性炭纤维为原材料,采用水洗和HNO3、H3PO4和HF酸洗方法对其进行预处理。利用扫描电镜、比表面积测定仪及傅立叶红外光谱仪对其表面形貌和结构进行表征,并通过测定灰分含量、碘值和苯酚值考察其吸附性能。结果表明:预处理后活性炭纤维的形状和尺寸变得相对规整,表面酸性官能团数量增加,吸收谱峰变得尖锐,比表面积和总孔容增大。HF水浴去灰分效果最佳可达84.8%;H3PO4活化炭化的碘和苯酚吸附值最高,分别为1 925 mg/g和226 mg/g;而HNO3活化会造成表面刻蚀,碘和苯酚吸附值最低。确定H3PO4活化炭化为本实验最佳预处理方法。

Influence of different pretreatment methods on structure and adsorption property of activated carbon fibers

Activated carbon fiber was pretreated by water washing, HNO3, H3PO4, and HF pickling methods. Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) analysis, and Fourier transform infrared spectroscopy (FTIR) were used to examine the surface morphology and structure. The adsorption property was examined by measuring the ash content, iodine, and phenol values. The results showed that the activated carbon fiber has a relatively regular shape and size, and the number of surface acidic functional groups increased, the absorption peaks became sharper, and specific surface and pore volume increased after pretreatment. Using a HF bath was the best method of removing ash and the efficiency can be up to 84.8%. The H3PO4 activation charring process gave the highest iodine and phenol adsorption values, which were 1 925 and 226 mg/g, respectively. The iodine and phenol adsorption values obtained through the HNO3 activation charring process were the lowest because HNO3 can cause surface etching of the fiber. H3PO4 activation charring was identified as the best pretreatment method.