摘要
通过水热法制备了掺杂氧化石墨烯(GO)的金属有机框架GO@MIL^(-1)01,并考察了GO掺杂量对GO@MIL^(-1)01形貌和性质的影响规律。GO的掺杂影响了MIL^(-1)01晶体的形成过程。随着GO掺杂量的增加,GO@MIL^(-1)01晶体的完整性降低、粒径减小,团聚现象越发显著。GO@MIL^(-1)01能够有效去除溶液中的Cr(Ⅵ),该过程符合拟二级动力学方程。由Langmuir吸附等温线拟合得到的最大吸附量与GO掺杂量有关,在2%[相对于Cr(NO_3)_3·9H_2O质量]时达到最大,这与此时GO@MIL^(-1)01同时具有较大的比表面积和较大的孔体积有关。Cr(Ⅵ)的去除过程伴随着溶液中3NO-浓度的升高以及pH的下降,电荷平衡计量分析表明MIL^(-1)01和GO@MIL^(-1)01对Cr(Ⅵ)的去除机制相同,主要依靠MIL^(-1)01的离子交换作用,并且所去除的Cr(Ⅵ)以24CrO-形式存在于固相中。
A novel composite （GO@MIL-101） containing metal organic framework （MIL-101） and graphene oxide （GO） was prepared by hydrothermal method. The effects of GO concentration on the composite morphology and structure were investigated. The doping of GO affected the crystallization of MIL-101 and its integrity reduced with the increase in GO concentration. The crystal size decreased and the agglomeration phenomenon became significant. GO@MIL-101 can be used to remove Cr（Ⅵ） from aqueous solution, and the removal kinetics can be fitted by the pseudo-second-order kinetic model. The maximum Cr（Ⅵ） uptake capacity obtained by Langmuir adsorption isotherm depended on the GO concentration. When the GO concentration of 2% [based on the mass of Cr（NO3）3 - 9H20] was applied, GO@MIL-101 exhibited higher Cr（Ⅵ） uptake capacity compared to MIL-101 due to its larger specific surface area and pore volume. The removal of Cr（Ⅵ） was accompanied by the release of NO3 and the decrease of pH. The charge balance analysis indicated that the removal mechanism involved in the Cr（Ⅵ） removal by MIL-101 and GO@MIL-101 was mainly ion exchange. The removed Cr（Ⅵ） existed in the form of CRO24- in the adsorbent.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2017年第5期2105-2111,共7页
CIESC Journal
基金
国家自然科学基金项目(51638011
51478314
51138008)
国家重点基础研究发展计划项目(2016YFC0400503)
天津市自然科学基金项目(14JCQNJC09000)
天津市科技计划项目(14ZCDGSF00128)~~
