空心贵金属纳米材料的制备及其在电化学传感器中的应用

发布时间：2018-03-14 19:43

本文选题：贵金属　切入点：空心结构　出处：《重庆理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：电化学传感器因灵敏度高、稳定性好、能进行快速实时监测等特点,已在临床诊断、环境监测、食品检测等领域得到广泛的应用。电极材料的电催化活性是影响传感器参数指标的重要因素,贵金属催化剂以其较高的催化活性和化学稳定性,成为当前催化研究领域的热点课题。具有空心结构的贵金属纳米材料综合了空心结构和贵金属纳米粒子的优点,具有大的比表面积及丰富的孔洞结构,能够容纳大量的客体分子或尺寸较大的分子,具有较多的催化活性位点,电催化活性大幅度提高,在生物化学、催化化学、材料科学等领域具有特殊的应用前景。本论文拟以Cu2O为牺牲模板,利用Cu2O和贵金属前驱体溶液之间的自发氧化还原反应设计合成单元或二元的贵金属空心结构材料,同时对该空心结构材料的微观形貌进行解构,对其成分进行分析。研究了该空心材料修饰电极对葡萄糖和过氧化氢的电化学检测能力,通过电化学方法对电化学传感器的性能指标进行了标定,该空心结构对葡萄糖和过氧化氢均表现出较高的电催化活性。该论文的研究将为贵金属空心结构在生物分子电催化领域的应用提供理论支持和指导意义,主要研究内容如下:(1)采用液相法制备了立方结构的Cu2O,并用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线衍射(XRD)对其形貌和结构进行了表征,结果表明,实验得到了纯净的单相实心赤铜矿Cu2O晶体,平均粒径400 nm左右。(2)以Cu2O为模板,将H2PtCl6溶液加入到Cu2O悬浮液中,两者发生氧化还原反应使铂负载在Cu2O表面,随后,酸蚀去除模板,得到Pt空心纳米结构材料。采用SEM和TEM对其形貌进行了表征,构建了基于Pt空心纳米材料的葡萄糖电化学传感器,采用循环伏安法(CV)和计时电流法(CA)研究了其修饰电极对葡萄糖的电催化氧化性能。实验结果表明,该传感器对葡萄糖的催化氧化电流与其浓度在0.5mM-22.5 mM范围内呈现良好的线性关系,检出限为0.26 mM,灵敏度为92.03μA/mM/cm2。(3)以Cu2O为模板,将H2PtCl6溶液和Na2PdCl4溶液按摩尔比1:1先后加入到Cu2O悬浮液中,酸蚀去除模板,得到Pt/Pd空心纳米材料。采用SEM、TEM和X射线能量色散谱(EDS)对其形貌结构进行了表征,构建了基于Pt/Pd空心纳米材料的H2O2电化学传感器,采用CV和CA研究了其修饰电极对H2O2的电催化性能。实验结果表明,该传感器对H2O2的催化电流与其浓度在0.25 mM-30 mM范围内呈现良好的线性关系,检出限为0.12 mM,灵敏度为77.66μA/mM/cm2。(4)采用相同的模板法制备空心金纳米材料,通过研究氯金酸用量、腐蚀剂种类等因素对产物形貌的影响后,均未得到期望的空心结构。由于负载型金纳米粒子同样表现出极高的电催化活性,实验中研究了Au-Cu2O复合材料修饰电极对H2O2的电化学检测性能。实验结果表明,Au-Cu2O复合材料对H2O2有较高的电催化活性,电化学传感器的线性范围为0.025 mM-11.2 mM,检出限为1.05μM,灵敏度为292.89μA/mM/cm2,该材料在H2O2的快速检测方面有潜在的应用价值。
[Abstract]:Electrochemical sensor because of high sensitivity, good stability, can real-time monitoring and other features, has been in clinical diagnosis, environmental monitoring, widely used in food detection. The electrocatalytic activity of the material is an important factor affecting the parameters of the sensor, noble metal catalysts because of their relatively high catalytic activity and chemical stability, become a hot topic in the field of catalysis. With noble metal nanomaterials with hollow structure combines the advantages of hollow structure and noble metal nanoparticles, with large surface area and abundant pore structure, can accommodate a large number of guest molecules or the size of the molecules, the catalytic site has more, greatly improve the electrocatalytic activity in Biochemistry, chemistry, catalysis, has the application prospect of special materials science and other fields. This paper intends to use Cu2O as sacrificial templates, Cu2O and precious metals The hollow noble metal structure materials synthesis unit two yuan design or spontaneous oxidation between the precursor solution and reduction, morphology of the hollow structure material deconstruction, analysis its composition. Study on glucose and hydrogen peroxide electrochemical detection ability of the hollow materials modified electrode by electrochemical method on performance index electrochemical sensors were calibrated, the hollow structure of glucose and hydrogen peroxide exhibited higher electrocatalytic activity. The study will provide theoretical support and guidance for the application of hollow noble metal structure in the biological molecules in electrocatalysis, the main contents are as follows: (1) using the cubic structure Cu2O liquid method, by using scanning electron microscope (SEM), transmission electron microscopy (TEM) and X ray diffraction (XRD) on the morphology and structure were characterized. The results show that, The pure single-phase solid copper Cu2O crystal, the average particle size of about 400 nm. (2) using Cu2O as template, H2PtCl6 solution was added to the Cu2O suspension, the two oxidation platinum loading on the surface of Cu2O reduction reaction subsequently, etching to remove the template, Pt hollow nano structure materials are used. The morphology was characterized by SEM and TEM, constructed the Pt hollow glucose electrochemical sensor based on Nanomaterials by cyclic voltammetry (CV) and chronoamperometry (CA) on the electric catalytic oxidation performance of the modified glucose. The experimental results show that the sensor for glucose oxidation current and the concentration of a good linear relationship in the range of mM 0.5mM-22.5, the detection limit was 0.26 mM, the sensitivity is 92.03 A/mM/cm2. (3) using Cu2O as template, H2PtCl6 solution and Na2PdCl4 solution after the first molar of 1:1 added to the Cu2O suspension In the acid etching to remove the template, Pt/Pd hollow nano materials. By using SEM, TEM and X ray energy dispersive spectroscopy (EDS) on the morphology and structure were characterized by H2O2 Pt/Pd electrochemical sensor was constructed based on hollow nano materials, studied the electrocatalytic performance of H2O2 electrode modified by CV and CA. The experimental results show that the catalytic sensor current on H2O2 and concentration showed a good linear relationship in the range of mM 0.25 mM-30, the detection limit was 0.12 mM, the sensitivity is 77.66 A/mM/cm2. (4) preparation of hollow gold nanoparticles using the same template method, through the study of chloroauric acid dosage, corrosion agent and other factors on the morphology of the product after have not been expected. Due to the hollow structure of supported gold nanoparticles also showed high electrocatalytic activity, we have studied the electrochemical detection of Au-Cu2O composite modified electrode for H2O2 measurement. The experimental performance The results show that Au-Cu2O composite has high electrocatalytic activity for H2O2. The linear range of the electrochemical sensor is 0.025 mM-11.2 mM, the detection limit is 1.05 M, and the sensitivity is 292.89 A/mM/cm2 A/mM/cm2. The material has potential application in the rapid detection of H2O2.

【学位授予单位】：重庆理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TP212.2

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