XJIPC OpenIR  > 环境科学与技术研究室
基于金属有机骨架化合物碳基材料的制备及其电化学传感应用研究
肖丽丽
学位类型博士
导师王富
2017-05-28
学位授予单位中国科学院大学
学位授予地点北京
学位专业材料物理与化学
关键词Mof衍生多孔碳 电化学传感器 重金属离子 氯霉素 对硝基苯酚
摘要

摘要金属有机骨架化合物(Metal-organic framework, MOF)是由金属离子与有机分子通过配位作用自组装而成的具有周期性网络结构的杂化材料。因其具有高的比表面积、极高的孔隙度、可调的孔径和多元化等特点,MOF在能量存储、气体吸附及分离、催化和分析等领域有着重要的应用。近十年来,以MOF作为前驱体或者模板剂制备碳基材料成为材料领域的研究热点。与传统的多孔碳基材料相比,MOF衍生碳基材料往往具有更高的比表面积、易修饰、易掺杂和结构更多元化等优点。例如通过简单调控MOF碳化氛围,可以选择性地制备多孔碳或者金属/金属氧化物掺杂的碳基材料。本论文致力于以MOF为前驱体制备多孔碳以及金属磷化物掺杂的多孔碳,并研究这些MOF衍生碳基材料在电化学传感环境污染物(重金属离子、氯霉素和对硝基苯酚)中的应用。一、采用溶剂热的方法,以锌离子作为金属中心,2,6-萘二羧酸作为有机配体,制备了羧酸类的金属有机骨架化合物IRMOF-8 (Isoreticular metal-organic framework-8)。在氮气氛围中,IRMOF-8经过1000 oC煅烧转化为只含氧元素的纯多孔碳,该多孔碳具有沟壑状的大孔以及大量的微孔和介孔。IRMOF-8衍生层级多孔碳(Nanoporous carbon, NPC)具有高的比表面积(1715 m2 g-1)和高的导电性。由于NPC高的比表面积、分级的孔隙,以及少量石墨化结构的碳等特点,基于NPC的电化学传感器对Pb(II)表现较高的灵敏度和极高的稳定性,线性范围是1 ~ 70 μg L-1,检测限是0.8 μg L-1。二、为了进一步提高MOF衍生多孔碳的分散性、铺展性以及拓展其在电化学传感中的应用,本章首次将溶剂剥离的方法应用于处理MOF衍生多孔碳:将IRMOF-8衍生多孔碳(DPC)分散于N-甲基吡咯烷酮(NMP)进行了超声处理制备超声剥离多孔碳(Exfoliated porous carbon, EPC),并应用于氯霉素的检测。研究发现NMP能很好地剥离DPC,使得DPC的尺寸大大地减小,且不破坏其多孔结构,得到了一种具有高比表面积(1854 m2 g -1)的EPC。相比较于DPC修饰电极,EPC修饰电极显著地提高了对氯霉素的电催化活性,这是因为溶剂剥离改善了DPC的分散性、铺展性以及增加其有效比表面积。在优化条件下,基于EPC的电化学传感器对氯霉素的检测灵敏度高达129.1 μA/(μmol L-1),检测范围是0.1 ~ 4.0 μmol L-1,检测限是2.9 ′10-9 mol L-1。三、基于前两章MOF衍生多孔纯碳的研究,本章采用氮原子掺杂进一步改进及拓展MOF衍生碳基材料的传感性能和传感应用。本章选择氮原子掺杂纳米级的ZIF-8(Zeolitic imidazolate framework-8)作为研究对象,ZIF-8是锌离子与2-甲基咪唑配位形成的具有菱形十二面体的沸石咪唑类金属有机骨架化合物。室温溶剂热法合成了纳米级的ZIF-8在氮气气氛中,经600 oC煅烧,其中锌离子转化为氧化锌,2-甲基咪唑则分解成为N掺杂的碳骨架,酸洗除去残留的氧化锌得到了N掺杂多孔碳。本工作以ZIF-8为前驱体制备的N掺杂微孔碳(Nitrogen doped microporous carbon, NMC)很好地保持了ZIF-8的菱形十二面体形貌。该NMC具有高的比表面积(941 m2 g-1),高的N含量(25 at.%)。结合Nafion和铋膜,我们构筑了基于NMC的电化学传感器能同时检测Cd(II)和Pb(II),其检测限分别是1.5 μg L-1和0.05 μg L-1。四、基于前面工作发现氮原子掺杂的MOF衍生纳米多孔碳具有优异的电化学传感性能,本章结合磷化钴高催化活性和氮原子掺杂MOF衍生多孔碳的优势,制备了新型磷化钴和氮原子共掺杂的多孔碳球,并研究其在电化学传感对硝基苯酚中的应用。首先通过溶剂热法制备了球状的Zn(PO4)x,以Zn(PO4)x作为模板剂,在其表面原位生长了一层ZIF-67,从而制备了Zn(PO4)x和ZIF-67复合的Zn(PO4)x@ZIF-67微球。吸附在Zn(PO4)x上的Co2+与2-甲基咪唑配位形成的ZIF-67能紧贴于Zn(PO4)x表面生长,得到的Zn(PO4)x@ZIF-67保持原有的球形,尺寸略有所增加。在氮气保护氛围中,Zn(PO4)x@ZIF-67经900 oC碳化,然后在氧化条件下酸洗得到了磷化钴(CoxP)和N共掺杂的MOF衍生碳基材料(CoxP/NC)。该CoxP/NC碳基材料具有较高的比表面积(826 m2 g-1)以及分布均匀的CoxP,在电化学检测对硝基苯酚(4-NP)中表现出极高的催化活性。本工作中所用的球状Zn(PO4)x既是模板剂,同时也充当了磷源,实现了一步法合成石墨烯包裹的CoxP以及N掺杂的碳基微球。该CoxP/NC修饰电极对4-NP具有极高的检测灵敏度(20.9 μA/(μmol L-1) )和极低的检测限(2.0′10-9 mol L-1)。本论文以MOF作为前驱体制备了几种不同形貌和结构的碳基材料,并研究这些碳基材料修饰电极在电化学检测环境污染物中的应用。MOF衍生碳基材料具有极高的比表面积,能有效地吸附待测物;高的导电性,有利于电化学反应电子的传输;极高的化学稳定性,有利于电化学信号的稳定。由此可见,MOF衍生碳基材料在电化学分析领域有着重要的研究和应用价值。

其他摘要

Abstract Metal-organic framework (MOF) is a kind of highly crystalline hybrid materials that can be self-assembled through the coordination of inorganic metal ions/clusters and organic ligands. Due to its high porosity, ultrahigh surface area, tunable pore sizes and diversity of structure, MOF has attracted extensive attention and made enormous contributions in the development of energy storage, gas adsorption and separation, heterogeneous catalysis and chemical sensing. In the last decade, the emerging carbon-based nanomaterials derived from MOF have been a hot research topic due to its unique features including extremely high surface area, hierarchical porosity, good conductivity, tunability of structures and easy functionalization. Pure nanoporous carbon or metal doped carbon materials can be easily and selectively prepared through modulation the annealing and acid pickling conditions. This thesis focuses on preparation of pure nanoporous carbon and metal phosphide doped carbon derived from MOF, as well as application of the MOF-derived carbon-based nanomaterials in electrochemical sensing of environmental pollutants. The main contents of this thesis are summarized as follow:1. A isoreticular metal-organic framework-8 (IRMOF-8) prepared from the coordination of zinc ion and 2,6-naphthalenedicarboxylic acid was synthesized by the solvothermal method. A three-dimensional and hierarchical nanoporous carbon material (NPC) was prepared by simple pyrolysis of IRMOF-8 at 1000 oC in nitrogen. The results is found that the as-synthesized NPC possessed a high surface area (1715 m2 g-1) and decent conductivity. A sensitive electrochemcial sensor for Pb(II) was further fabricated based on NPC with assistance of Nafion and bismuth films. The Pb(II) sensor exhibited excellent repeatability and good selectivity due to the three-dimensional hierarchy of NPC. A linear ranges of 1-70 μg L-1 and the detection limit of 0.8 μg L-1 were achieved at NPC modified electrode. 2. In order to improve the dispersibility and expand the electrochemical application of IRMOF derived porousa carbon (DPC), solvent exfoliation was firstly applied to develop exfoliated porous carbon (EPC) for detection of chloramphenicol (CAP) in this work. In comparison with DPC, EPC showed an increscent surface area (1854 m2 g-1), improved spreadability and dispersibility benefiting from N-methyl-2-pyrrolidone (NMP) exfoliation. In addition, the EPC modified GCE (EPC/GCE) showed the apparently better electrochemical activity toward CAP than that of the DPC/GCE. Under the optimized conditions, the EPC/GCE exhibited very high sensitivity of 129.1 μA μmol-1 L and a very low detection limit of 2.9×10-9mol L-1.3. Nitrogen doping was employed for further improving the electrochemical properties and expanding the application of MOF-derived porous carbon in this work. ZIF-8 (made from the coordination of zinc ion and 2-methylimidazole) therefore was selected for its nanoscale and abundant nitrogen. The as-synthesized ZIF-8 exhibits the rhombic dodecahedral morphology with a particle size of 80 nm. N doped microporous (NMC) was prepared by carbonization of ZIF-8 in 600 oC, in which 2-methylimidazole served as N dopant. NMC inherited the rhombic dodecahedral morphology from ZIF-8 and have reduced particle size of 40 nm. Due to its good dispersibility, high specific surface area (941 m2 g-1) and abundant nitrogen content (25.0 at.%), the NMC modified glassy carbon electrode can simultaneous detect trace of Cd(II) and Pb(II) with wide detection ranges and low detection limits (1.5 μg L-1 for Cd(II) and 0.05 μg L-1 for Pb(II)). 4. Based on the above works, the nitrogen and cobalt phosphide co-doped porous carbon microsphere was developed for expanding the application of the ZIF-derived porous carbon in this work. An amorphous Zn(PO4)x sphere was firstly synthesized from sodium phosphate and zinc ion by solvothermal. These Co2+ absorbed on Zn(PO4)x coordinated with 2-methylimidazole to in-situ grow ZIF-67 for receiving Zn(PO4)x@ZIF-67. A novel N-doped porous carbon hybrid materials embedded with CoxP (CoxP/NC) was facilely prepared by pyrolysis of Zn(PO4)x@ZIF-67 at 900 oC in nitrogen, in which Zn(PO4)x spheres acted as the template and phosphorus source simultaneously. The obtained CoxP/NC exhibited uniform distribution of CoxP wrapped by graphitic carbon layers, high surface area (826 m2 g-1) and good conductivity. Moreover, the as-synthesized CoxP/NC showed excellent electrochemical catalytic activity toward 4-nitrophenol (4-NP) due to the uniform distribution of CoxP, upper surface area of CoxP/NC, abundant mesopores, as well as good conductivity. It was found that the 4-NP sensor based on CoxP/NC showed a very high sensitivity of 20.9 μA μmol-1 L and a very low detection limit of 2.0×10-9 mol L-1 . In summary, a series of porous carbon materials with different morphology and structure were facilely prepared by using MOF as the precursor through pyrolysis. These MOF-derived carbon materials could be a promising candidate for electrochemical sensing environmental pollutants, such as heavy metal ions, chloramphenicol and 4-nitrophenol, because the high surface area, good conductivity and well chemical stability are benefit to the absorption of the analytes, electron transport and stabilization of electrochemical signal.

文献类型学位论文
条目标识符http://ir.xjipc.cas.cn/handle/365002/4940
专题环境科学与技术研究室
作者单位中国科学院新疆理化技术研究所
推荐引用方式
GB/T 7714
肖丽丽. 基于金属有机骨架化合物碳基材料的制备及其电化学传感应用研究[D]. 北京. 中国科学院大学,2017.
条目包含的文件
文件名称/大小 文献类型 版本类型 开放类型 使用许可
基于金属有机骨架化合物碳基材料的制备及其(8593KB)学位论文 开放获取CC BY-NC-SA浏览 请求全文
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[肖丽丽]的文章
百度学术
百度学术中相似的文章
[肖丽丽]的文章
必应学术
必应学术中相似的文章
[肖丽丽]的文章
相关权益政策
暂无数据
收藏/分享
文件名: 基于金属有机骨架化合物碳基材料的制备及其电化学传感应用研究.pdf
格式: Adobe PDF
此文件暂不支持浏览
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。