【作者】 王蕾；

【导师】 方建； 赵继华；

【作者基本信息】 兰州大学 ， 化学·物理化学， 2016， 硕士

【摘要】 目前,随着经济的飞速发展,能源缺乏、环境污染以及食品安全等问题逐渐显露并获得越来越多的关注。过渡金属氰化物具有化学稳定性好、氧化还原特性、电催化性能优越、制备方法温和、造价低、环境污染小等优点,是设计电化学传感器的理想修饰电极材料和制备相应金属基纳米材料的优秀模板。因此,本论文制备了两种以普鲁士蓝（PB）为主要成分的电化学传感器,分别应用于电催化检测亚硝酸盐及L-半胱氨酸;还制备了一种以钴普鲁士蓝类似物（Co-Co PBA）为模板的钴氧化物,应用于电催化水氧化研究。主要内容如下:1.制备石墨烯量子点（GQDs）并将其负载在石墨毡（GF）电极表面,利用GQDs促进溶液中[Fe（CN）₆]^3-与Fe³⁺反应生成大量PB,在GF表面形成PB@GQDs复合膜,通过恒压电沉积在其表面覆盖一层聚吡咯膜（PPy）以增加电极的稳定性,得到聚吡咯及石墨烯量子点@普鲁士蓝复合膜石墨毡电极（PPy/PB@GQDs/GF）。再利用扫描电镜（SEM）、透射电镜（TEM）、红外光谱（FTIR）、X-射线衍射（XRD）、以及电化学方法等手段对复合电极材料进行表征,并利用紫外可见分光光度法证明了GQDs对生成PB的促进作用。然后将该复合电极应用于电催化检测L-半胱氨酸,结果表明该传感器具有低检测限、高灵敏度、宽检测范围以及很好的电化学稳定性,并且能够应用于实际样品的检测。2.以石墨毡（GF）为基底,利用负载的离子液体（[Bmim][BF4]）促进普鲁士蓝纳米粒子（PB）的合成,制备了普鲁士蓝/1-丁基-3-甲基咪唑四氟硼酸盐-石墨毡三元复合电极（PB/[Bmim][BF4]-GF）。再利用扫描电镜（SEM）、红外光谱（FTIR）以及X-射线衍射（XRD）等手段对复合材料进行表征,并利用紫外可见分光光度法证明了[Bmim][BF4]可以加快[Fe（CN）₆]^3-与Fe³⁺反应生成PB的反应速率。然后将该复合电极应用于亚硝酸盐的检测,结果表明该传感器具有较低的检测限、高灵敏度以及很好的电化学稳定性,并且在实际样品的检测中有很好的效果。3.以钴普鲁士蓝类似物（Co-Co PBA）为模板,掺杂Mn后通过空气中热分解制备了中空多孔结构的Mn-Co₃O₄纳米匣,利用扫描电镜（SEM）、透射电镜（TEM）、红外光谱（FTIR）、X-射线衍射（XRD）,X射线光电子能谱（XPS）等手段对材料进行表征。发现Mn-Co₃O₄和Co₃O₄纳米匣虽然形貌类似,但是掺杂Mn有利于增加纳米材料的电化学反应活性位点,从而提高了其电催化水氧化反应的性能,具有较低的初始反应电位、较小的Tafel斜率以及在电流密度为10 mA cm-2时有较小的反应过电位。更多还原

【Abstract】 Along with the rapid development of economies, the problems about energy, environment and food safety are gradually appeared and attract more and more attention. Due to their advantages such as good chemical stability, redox, excellent electrocatalytic properties, soft synthesis method, low cost and less environmental damage, transition metal hexacyanometalates are promising modified electrode materials for design and fabrication of electrochemical sensors and excellent templates for the synthesis of metal based nanomaterials. Therefore, in this paper, two kinds of electrochemical sensors were fabricated mainly based on Prussian blue（PB） and applied on electrocatalytic detection of nitrite and L-cysteine, respectively. Also, a kind of cobalt oxide based on the cobalt hexacyanocobaltates（Co-Co PBA）, which was used as a template, was synthesized and applied as a catalyst for electrocatalytic water oxidation. The main work is as follows:1. Graphene quantum dots（GQDs）, which were synthesized and grafted on the surface of graphite felt（GF）, were used to promote the synthesis process of redox reaction between Fe³⁺ and [Fe（CN）₆]^3- in aqueous solution and thus form PB@GQDs composite film on the surface of GF. The PPy film was electro-polymerized on the surface of electrode for improving the electrochemical stability, so the PPy/GQDs@PB/GF had been fabricated. Then the as-prepared electrode was characterized by scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, Fourier tansform infrared spectroscopy（FTIR）, X-ray diffraction（XRD） and electrochemical methods. The promotion effect of GQDs for the formation of PB was verified by UV- vis spectrophotometry as well. It exhibited an excellent activity for the electrocatalytic detection of L-cys, with a high sensitivity, a low detection limit, a wide detection range, as well as a remarkable long-time stability and a good response to practical analytes, were also ascertained.2. A novel Prussian blue（PB）, ionic liquid 1-butyl-3- methylimidazolium tetra?uoroborate（[Bmim][BF4]） and graphite felt（GF） nanocomposite electrode（PB/[Bmim][BF4]-GF） was obtained on the substrate of GF, which was grafted with [Bmim][BF4] to accelerate redox reaction process between Fe³⁺ and [Fe（CN）₆]^3- for the synthesis of PB. The as-prepared electrode material was characterized by scanning election microscopy（SEM）, Fourier tansform infrared spectroscopy（FTIR） and X-ray diffraction（XRD） and electrochemical methods. The promotion effect of [Bmim][BF₄] for the formation of PB was verified by UV- vis spectrophotometry as well. Then the PB/[Bmim][BF4]-GF composite electrode was used to detect nitrite. The sensor displays remarkable sensitivity, extremely low detection limit, as well as a long-time stability and a good response to practical analytes.3. The Mn-Co₃O₄ nanobox with hollow porous structure was synthesized by thermal decomposition of Mn doped cobalt hexacyanocobaltates（Co-Co PBA） and characterization by scanning electron microscopy（SEM）, transmission electron microscopy（TEM）, fourier tansform infrared spectroscopy（FTIR）, X-ray diffraction（XRD） and X-ray photoelectron spectroscopy（XPS） methods. The structure of Mn-Co₃O₄ nanobox was found to be similar to Co₃O₄ nanobox. However, doping Mn is in favor of the increase of electrochemical active sites of t he nanomaterials, and thus improving the electrocatalytic water oxidation property. The as-prepared Mn-Co₃O₄ nanobox exhibits a low onset potential, a small Tafel slope and a low overpotential when the current density is 10 m A cm-2.更多还原