XJIPC OpenIR  > 资源化学研究室
介孔二氧化硅/碳材料在电化学检测环境污染物方向的应用
王乐
学位类型硕士
导师胡广志
2018-05-25
学位授予单位中国科学院大学
学位授予地点北京
学位专业物理化学
关键词介孔材料 重金属离子 过氧化氢 电化学传感器 阳极溶出伏安法 计时电流法
摘要

介孔材料自出现以来一直受到学界的广泛关注,这不但因为其拥有独特的2D表面形貌及3D结构特性,更因为它在较大的比表面积上拥有更多的反应位点,这些反应位点有利于诸如吸脱附、催化和电化学等依赖于表面特性的反应过程的进行,其独特可调的单分子中空结构打破了传统多孔材料(如沸石)在孔径尺寸上的限制,使其在表面化学研究方面显示出先天的优势,纳米级结构的材料因为纳米尺度效应(包括量子效应,表面结构效应,限域效应)使得纳米材料在传感等方面的应用上大放异彩。有序介孔材料的粒径尺度都是在微米级别的,这使得其除了能在包括如吸附、过滤分离在内的普通工业流程中有重要应用,同时也不失纳米材料所拥有的一些特性。在电化学检测领域,介孔材料因为有较大的比表面积有效提高了双电层面积,丰富的孔道有利于物质的传递,拥有较多的活性位点等优点一直被人们关注。本论文主要是以制备介孔材料作为电极修饰材料,并以此组装电化学传感器对溶液中如重金属离子、H2O2等污染物进行检测。 一、制备了介孔材料SBA-15,对其进行了形貌表征,证明了介孔结构的存在。使用SBA-15修饰了玻碳电极制备了SBA-15/Nafion/GCE电极,并对该传感器进行了电化学表征, SBA-15由于其独特的多孔结构有利于铜的沉积与富集,且拥有较大的表面积,有效分散了Nafion,相当于增加了电极的有效面积,从而在Cu(II)的检测实验中取得了较好的效果。使用DPASV对溶液中的Cu(II)进行了测量并得到了线性工作曲线,SBA-15/Nafion/GCE的线性范围为1-150 μg/L,线性方程为y=0.217x-0.134(R2=0.996)。在实际的应用中,SBA-15/Nafion/GCE也有良好的抗干扰能力。二、使用二氧化硅为模板包覆聚苯并噁嗪途径合成的N掺杂中空多孔碳球(N-HPCS)拥有平整均一的中空球状结构,而且在球体的表面壳层上散布着轮廓分明的孔道。这一结构结合原位铋膜电镀在使用差分阳极溶出伏安法(DPASV)检测痕量Cd(Ⅱ) 显示出很好的性能。在最优实验条件下,使用原位电镀铋膜N掺杂中空多孔碳球(Bi-N-HPCS)修饰的电化学传感器对Cd(Ⅱ) 响应良好,线性响应范围从0.5 μg L-1到150 μg L-1,同时在三倍信噪比下检测限(LOD S/N=3)为0.21 μg L-1左右,这一浓度比美国环境保护部(EPA)所给出的安全饮用水标准低了20多倍。基于其出色的检测性能,此电化学组装传感器对监测中体中Cd(Ⅱ)污染有很好的应用前景。三、通过硬模板法合成了一种原子级掺杂Fe-N 结构分散于N掺杂介孔碳表面的(Fe/NOMC)有序介孔碳复合材料,并使用该材料组装了一种能对溶液中低浓度H2O2进行检测的无酶电化学传感器。我们对制备的Fe/NOMC的形态学结构和性质进行了研究,并使用包括透射电子显微镜(TEM)、能量弥散X射线探测器(EDX)、小角X射线衍射仪、氮气吸脱附测试仪在内的实验设备对材料进行了表征。之后,我们对Fe/NOMC作为电极材料的电化学检测性能进行了研究,将材料修饰于玻璃碳电极(GCE)上,通过循环伏安法和计时电流法的检测不同修饰电极对H2O2浓度变化所产生的信号变化,并由此评价该组装电化学传感器对过氧化氢检测效果的优劣。实验结果表明,Fe/NOMC在进行定量检测溶液中H2O2有着十分优秀的表现,和其他无酶电极材料相比,该材料有着更宽的检测浓度范围(8-23000 μM)、更低的检测限(LOD)(5 μM)和较快的响应速度(2 s内),在其线性范围内,在线性范围内相关系数高达0.998,并且Fe/NOMC的抗干扰能力也十分优异,非常有进行实际应用的价值。

其他摘要

mesoporous materials have inspired prominent research interests due to their unique features in 3D structures and 2D interfaces. A large number of reaction/interaction sites are related with the high surface area, which have benefits for the interface-related processes such as sorption, separation, catalysis and electrochemistry applications. The uniform and tunable large pores afford enough monodispersed void spaces for large molecules and hence break through the size restriction of conventional microporous materials (zeolites), showing advantages in catalysis involving large molecules, adsorption, separation, drug and DNA delivery, etc. The uniform nanosized framework structures bring nanoeffects (surface and quantum effects), which endow the materials good performance in sensors, Li - ion batteries and nanodevices. In all, the widely practical of mesoporous materials can be expected, especially in electrochemical analysis. The ordered mesoporous promote the diffusion of reactants; more active centers enable faster electron transfer on the electrode and enhance the adsorption and reaction. In this paper, the preparation of mesoporous materials is used as electrode modification material, and the electrochemical sensor is used to detect the pollutants such as heavy metal ions and H2O2 in the solution as the main content. 1. The mesoporous materials-SBA-15 was synthesized in this work. Their morphology characterization which proved the existence of mesoporous structure was carried on in STEM and SEM. SBA-15 modified Glassy carbon electrode which was tested by electrochemical analysis is performance well because of the advantages of SBA-15 that its unique porous structure make for copper deposition and enrichment, and its larger surface area makes Nafion dispersed well. Therefore, a good result were obtained in Cu(II) detecting which used by DPASV method in the solution, and the linear working curve was obtained, the linear range of SBA-15 /Nafion/GCE is 1-160 μg/L. The linear equation is y=0.217x-0.134 (R2=0.996)2. N-doped hollow porous carbon sphere (N-HPCS) was synthesized by silicon dioxide template-assisted polybenzoxazine (PB) coating strategy. The prepared N-HPCS has a smooth hollow ball structure surrounded by a welldefined porous shell. Combining with in-situ plating of Bi film, the N-HPCS was further fabricated a sensitive electrochemical platform for determination trace levels of Cd(II) by differential pulse anodic stripping voltammetry (DPASV). Under the optimized conditions, the Bi-N-HPCS based sensor displays a linear response to Cd(II) over the range of 0.5 μg?L-1 to 150 μg?L-1. Meanwhile, the limit of detection (LOD, S/N=3) is estimated to be around 0.21 μg?L-1 for Cd(II), which is 20 more times lower than the safety values set by United States Environmental Protection Agency (EPA) for the drinking water. Due to the excellent analytical performance, the fabricated electrode is promised for future development in monitoring of cadmium pollution in the environment.3.A novel N-doped mesoporous carbon by atomically dispersed Fe-N dopant composite modified electrode (Fe/NOMC) was prepared by hard template approach and then fabricated non-enzymatic sensor was used for H2O2 determination. The morphology and property of Fe/NOMC composite was characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), small angle X-ray diffraction (XRD) spectrum and nitrogen-sorption measurement, respectively. The electrochemical sensing performance of the Fe/NOMC composite modified glassy carbon electrode (GCE) was studied by cyclic voltammetry and chronoamperometry methods. An excellent performance towards hydrogen peroxide reduction was achieved in a wide range of 8-23000 μM, with limitation of detection (LOD) about 5 μM and a correlation coefficient of 0.998, as well as a short response time (2 s) and good selectivity.

页数62
文献类型学位论文
条目标识符http://ir.xjipc.cas.cn/handle/365002/5431
专题资源化学研究室
推荐引用方式
GB/T 7714
王乐. 介孔二氧化硅/碳材料在电化学检测环境污染物方向的应用[D]. 北京. 中国科学院大学,2018.
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
介孔二氧化硅碳材料在电化学检测环境污染物(2306KB)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
[王乐]的文章
百度学术
百度学术中相似的文章
[王乐]的文章
必应学术
必应学术中相似的文章
[王乐]的文章
相关权益政策
暂无数据
收藏/分享
文件名: 介孔二氧化硅碳材料在电化学检测环境污染物方向的应用.pdf
格式: Adobe PDF
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。