磁性Fe_3O_4/改性焦炭的制备及其降解性能

Preparation and degradation properties of magnetic Fe_3O_4/modified coke

以KOH为活化剂对焦炭进行活化制备改性焦炭,并采用原位氧化沉淀法制备出Fe_3O_4/改性焦炭,采用扫描电子显微镜(SEM)、N2吸附脱附(BET)、傅里叶交换红外光谱(FTIR)、X射线衍射(XRD)及振动样品磁强计(VSM)对样品进行表征,并且研究了其对罗丹明B的催化降解性能。结果表明,改性焦炭表面粗糙,孔结构发达,含氧官能团丰富,Fe_3O_4分散且牢固地负载于改性焦炭上,其粒径比纯Fe_3O_4小。Fe_3O_4/改性焦炭具有超顺磁性,对罗丹明B的降解为拟一级反应,其降解的最佳条件为:催化剂用量为0.8g/L,H2O2初始浓度为30mmol/L,p H为3.0,温度为35℃。Fe_3O_4与改性焦炭存在协同催化作用,罗丹明B的去除率可达98.85%。Fe_3O_4/改性焦炭是一种稳定、易磁分离回收利用的磁性催化剂。

Modified coke was firstly prepared from coke by KOH activation and then Fe3O4/modifiedcoke was prepared by in-situ oxidation precipitation method.The catalyst and samples werecharacterized by scanning electron microscopy(SEM),nitrogen adsorption isotherms(BET),Fouriertransform infrared spectroscopy(FTIR),X-ray powder diffractometer(XRD)and vibrating samplemagnetometer(VSM),and the catalytic degradation performance of Rhodamine B(RhB)was studied.The results show that the modified coke has rough surface and well-developed pore structure.Moreover,the oxygen-containing functional groups of modified coke are abundant.Fe3O4wasdispersed and firmly loaded on the modified coke,making the latter is smaller than the pure Fe3O4.Fe3O4/modified coke possessed superparamagnetism,and its degradation of RhB could be regarded aspseudo first-order reaction.The best degradation conditions were as follow:[catalysts]=0.8g/L,initial[H2O2]=30mmol/L,pH=3.0and T=35℃.There is a synergistic effect between Fe3O4and modifiedcoke,giving rise to the removal rate of RhB of98.85%.Therefore,Fe3O4/modified coke is a magneticcatalyst with good stability and recyclability.