YIC-IR  > 中科院烟台海岸带研究所知识产出
铋基电极的构建及在海岸带水体金属检测中的应用
其他题名Design of Bismuth-based Electrodes and Their Application in Metal Determination in Coastal Waters
胡雪萍
学位类型博士
导师潘大为
2018-06
学位授予单位中国科学院大学
学位授予地点中国科学院烟台海岸带研究所
学位名称工学博士
学位专业环境科学
关键词铋基材料 修饰电极 海岸带水体 金属检测 Bismuth-based Materials Modified Electrode Coastal Waters Metal Determination
摘要

海岸带作为海洋和陆地的交汇地带,受人类高强度活动以及全球气候变化双重影响,是具有独特的陆、海属性的复杂且动态的自然生态系统。海岸带水体主要包括近岸海水、入海河流、近岸湖泊、近岸水库等。海岸带作为海洋开发活动的基地,其水体中微/痕量金属的浓度和分布直接与该区域的水产养殖、生态健康等紧密相关。建立适用于海岸带水体金属的检测方法,研究海岸带区域水体中金属的含量和分布,有利于获取海岸带水质情况,进行有效的监控和防治。

目前检测分析金属元素的方法很多,如分子光谱法、原子光谱法、质谱法、色谱法、电化学分析法等。这些方法各有所长,但也都存在各自的不足。相比其它检测方法,电化学分析方法灵敏度较高、分析速度快,并且仪器设备简单,易于微型化和集成化,有助于实现现场检测和在线实时监测。工作电极是电化学传感器的主要信号单元。汞电极在金属分析检测中有很好的应用,但是汞的毒性及其在储存运输方面的不便限制了它的进一步使用和发展。2000年,Wang等人提出使用铋膜电极代替汞电极。铋材料绿色环保,而且可以和金属形成合金,在金属检测方面有较高的灵敏度,并迅速成为金属分析中的重要电极材料。本论文针对铋膜电极存在的结构单一、溶液耐受性差、稳定性差等问题,构建了三种不同形貌的铋基材料修饰电极,并结合简单的样品前处理过程,对烟台入海河流中铁的形态和浓度分布进行了研究。通过对铋基电极进行改进,以期建立适合于海岸带水体金属分析的高效、稳定的方法。主要研究内容如下:

1. 铋复合膜修饰电极的制备及在海岸带水体Pb(II)检测中的应用。采用一步电还原的方法制备了基于还原氧化石墨烯-铋(GR-Bi)复合膜材料的丝网印刷修饰电极,并用于Pb(II)的检测。GR导电性好,且具有大的比表面积和较多的吸附位点,可以为Bi的沉积提供附着点。结合石墨烯独特的结构、优异的性能以及铋可以和金属形成合金的特质,该GR-Bi复合膜材料修饰电极在Pb(II)的检测中表现出较好的效果。在最优检测条件下,该方法的线性范围为0.05~20 μM,检出限为6.8 nM,并成功应用于海岸带孔隙水中Pb(II)的检测。

2. 铋纳米片修饰电极的制备及在海岸带水体Fe(III)检测中的应用。以少量的氧化石墨烯为前驱体,合成了类似其片状结构的新型铋纳米片材料。氧化石墨烯的存在可以提高材料的分散性并促进二维片状材料的形成。所合成的铋纳米片材料的平均厚度为3~4 nm,平均长度为0.1~0.2 mm。基于铋纳米片材料独特的结构和性质,结合溴酸钾(KBrO3)催化体系的信号放大作用,该铋纳米片材料修饰电极对Fe(III)检测的线性响应范围为0.01~20 μM,检出限为2.3 nM。该方法最终成功应用于海岸带实际水体样品中总溶解态Fe的检测。

3. 铋棒修饰电极的制备及在海岸带水体Fe(III)检测中的应用。采用化学还原的方法,通过控制合成反应的条件,合成了棒状铋材料。对所合成的材料进行扫描电镜、X射线衍射和X射线光电子能谱表征,发现该铋材料呈现形状规整、棱角清晰的棒状结构,且同时含有金属铋和氧化铋的成分。棒状的结构可以提高材料在检测中的性能,氧化铋的存在可以提高材料在应用中的稳定性,而金属铋的存在可以提高材料在电化学检测中的灵敏度。基于铋棒材料修饰电极建立了Fe(III)检测的方法,并成功应用到海岸带实际水体Fe含量的测定中。

4. 铋棒修饰电极用于河水中不同形态Fe检测和流域分布研究。基于上述构建的铋棒材料修饰电极,结合简单的样品前处理步骤,采用电化学阴极溶出伏安法对流入烟台四十里湾的主要入海河流(逛荡河、辛安河、鱼鸟河)中不同形态铁(包括总铁、总溶解态铁和颗粒态铁)的浓度和分布进行了研究。结果表明:流入烟台四十里湾的逛荡河、辛安河、鱼鸟河水中,铁的形态主要以颗粒态铁为主,颗粒态铁占总铁的百分比分别为84.5%、87.6%和92.3%。从入海口到河流上游,铁浓度出现先增大后减小的现象。不同形态铁浓度与水体盐度(SA)呈负相关关系,与溶氧(DO)呈正相关关系,而与pH的相关性不明显。

5. 金膜(Au)修饰电极用于海水中不同形态Cu检测和定点分析研究。为与上述铋基材料修饰电极对比,构建了Au修饰电极。Au修饰电极制备较简单,可以通过电位清洗实现电极的更新和重复使用,且具有较高的稳定性。基于Au修饰电极,结合简单的样品前处理过程,采用电化学溶出伏安法对海水中不同形态的铜进行了测定。该方法无需复杂的样品处理和形态分离过程,可以直接在海水中进行测定,且不受海水高盐介质的影响,具有较好的准确性。使用该电极对黄海海域某站位点海水中不同形态铜(电活性态铜、酸溶解态铜、惰性态铜和总溶解态铜)的含量进行了连续十五天的测定。结果显示,该修饰电极灵敏、稳定,在海水连续分析检测中有较好的实用性。

6. 基于刻蚀ITO的金铋复合修饰电极的改进研究及在Fe形态分析中的应用。采用可一次性使用的商品化ITO电极作为基底,先对该基底进行电化学刻蚀形成粗糙表面,之后再对其进行电沉积修饰,通过该方法制备的金铋复合材料修饰ITO电极具有较高的稳定性。以金铋复合材料修饰的ITO为工作电极,采用电化学吸附阴极溶出伏安法,结合1-(2-吡啶偶氮)-2-萘酚(PAN)作为络合剂,构建了灵敏检测Fe(III)的分析方法。该方法结合简单的样品前处理过程,实现了对海岸带水体中总铁、总溶解态铁、颗粒态铁的测定。 

其他摘要

Coastal zone, which is the intersection of sea and land, is the unit under the dual influence of high intensitive human activity and global climate change, and has unique properties of land and sea. Coastal waters mainly include coastal seawater and waters derive from off-shore rivers, lakes, reservoirs and so on. Coastal zone is the core of the marine economic zone and the base of marine development activities. The concentrations and distribution of metals in coastal waters are closely related to aquaculture and ecological health. Developing a series of methods for metal detection and exploring the content and distribution of metals in coastal waters are helpful for obtaining the datas of water qulity and effectively monitoring and controlling the water environment.

To date, many analytical methods have been used for the determination of metals in waters, such as spectrometry, atomic spectroscopy, mass spectrometry, electrochemical methods, and so on. Each method has its own unique advantages and values, but each also has its own shortcomings. Comparing with other methods, electrochemical methods have a series of merits, such as simpleness, low-cost, fast, sensitive, easy to miniaturization and integration, being used in speciation analysis and suitable for on-line and in-situ determination. Working electrode is the core component of electrochemical sensor, directly determining the analysis performance. Mercury electrode has a positive effect on the detection of metals, but the toxicity of mercury and its inconvenience in storage and transportation limit its further use and development. Bismuth film electrode was first proposed by Wang in 2000. Bismuth was thought to be a promising alternative to mercury and was applied widely and quickly for its lower toxicity, ability to form alloys with metal and considerably sensitive voltammetric detection. Given that the bismuth film electrode has disadvantages of single structure, poor tolerance and poor stability, three kinds of bismuth-based electrodes have been constructed in this paper, and the content and speciation analysis of iron in main rivers of Yantai have been investigated combining simple sample pretreatments and cathodic stripping voltammetry. Through improving properties of bismuth-based electrode, the paper aims to establish a highly efficient and stable method for the analysis of metals in the coastal waters. The main contents of this research are as follows:

1. Preparation of bismuth composite film modified electrode and its application in Pb(II) detection. Reduced graphene oxide-bismuth (GR-Bi) composite film modified screen-printed electrode (SPE) was constructed through one-step electrochemical reduction method and used for the determination of Pb(II). Due to the large surface areas and a great deal of sites for particles, GR was used as a support for immobilization of bismuth particles with strong adhesion. Combined the unique structure and electronic properties of GR with the ability to form alloys of Bi, the GR-Bi/SPE had shown excellent electrochemical properties for determination of Pb(II). Under the optimal conditions, a good linear of 0.05~20 μM and a detection limit of 6.8 nM can be obtained based on anodic stripping voltammetry. Additionally, the GR-Bi/SPE was successfully applied to the rapid determination of Pb(II) in real coastal sediment pore water.

2. Preparation of bismuth nanosheets modified electrode and its application in Fe(III) detection. The article describes the synthesis of bismuth nanosheets (BiNSs) in the presence of a small quantity of grapheme oxide (GO) which is helpful for the formation of two dimensional BiNSs and improves dispersity. The average thickness and length of the BiNSs were 3~4 nm and 100~200 nm, respectively. Combining the unique nanostructure of the BiNSs, the ability of Bi to form alloys with metal, and the current amplification of the catalytic system, the modified electrode showed an excellent performance for electrochemical determination. Under the optimal conditions, the electrode had a linear response to Fe(III) in 0.01~20 μM concentrations range, with a lower detection limit of 2.3 nM. This method has been successfully applied to determine total dissolved iron in real coastal waters.

3. Preparation of bismuth microrods modified electrode and its application in Fe(III) detection. Bismuth-based microrods (BiMRs) were synthesized through a single reductant-controlled chemical reduction method. With the various quantity of reductant, different morphologies of bismuth-based materials were obtained. Characters of BiMRs were investigated by using scanning electron microscope (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that the product was uniform rods with a smooth surface and neat edges. Furthermore, BiMRs consisted of bismuth and bismuth oxide which made the material possess both advantages of metal and metal oxide. BiMRs had shown excellent electrochemical performance for Fe(III) determination and was successfully used for the determination of total dissolved iron in real water samples.

4. Speciation determination of iron and its spatial distribution analysis based on bismuth microrods modified electrode. In this work, different species of iron in coastal river water including total iron (TFe), total dissolved iron (TDFe) and particulate iron (PFe) had been determined through combining simple sample pretreatments and cathodic stripping voltammetry based on BiMRs modified electrode. Results showed that the main species of iron in three rivers was PFe, which accounts for 84.5%, 87.6% and 92.4%, respectively. The concentrations of iron from the estuary to the upstream regions increased firstly and then decreased. The iron concentration was negatively correlated with conductivity and salinity (SA), positively correlated with dissolved oxygen (DO) and had no obvious relations with pH values.

5. Voltammetric analysis of different species of copper in seawater based on gold film modified electrode. For comparison with bismuth-based electrodes mentioned above, this study investigated a gold film modified glassy carbon electrode (Au/GCE). Au/GCE can be continuously re-used following simple electrolytic cleaning with good measurement stability and reproducibility. Combined with simple sample pretreatment, Au/GCE was employed for the speciation analysis of copper in seawater by using a voltammetric method. This method was simple and effective for speciation analysis with no complicated pre-treatment or separation steps required, allowing for direct speciation analysis in real water samples with confirmed accuracy. The sensor was used for the fixed-point detection of electroactive copper, acid dissolved copper, inert copper and total copper for 15 days. The results showed that the modified electrode was sensitive, stable and had good practicability in the continuous analysis.

6. Preparation of gold-bismuth modified electrode based on etched ITO and its application in speciation analysis of iron. Commercial ITO electrodes were used as working electrodes, and rough surfaces were formed by electrochemical etching of ITO. Modify materials on the rough surface of ITO will result in working electrode with high stability. In this work, gold-bismuth modified ITO was employed as working electrode, and 1-(2-piridylazo)-2-naphthol (PAN) was introduced as complexing agent for Fe(III) to improve the sensitivity and selectivity. An analytical method for sensitive detection of Fe(III) was established based on electrochemical adsorption cathodic stripping voltammetry. Combined this method with sample pretreatment process, the determination of total iron, total dissolved iron and innert iron in the coastal waters have been successfully realized.

学科领域环境科学
目录

第1 章 绪论
1.1 海岸带水体金属污染现状 ....................................... 1
1.2 海岸带水体中金属的检测方法 ................................... 2
1.2.1 分光光度法.................................................. 2
1.2.2 原子光谱法.................................................. 3
1.2.3 电感耦合等离子体质谱法...................................... 6
1.2.4 电化学分析法................................................ 7
1.3 电化学溶出伏安法 ............................................. 8
1.3.1 溶出伏安法原理.............................................. 8
1.3.2 检测系统.................................................... 9
1.3.3 工作电极.................................................... 10
1.4 化学修饰电极在金属检测中的应用 ............................... 12
1.4.1 汞基修饰电极................................................ 13
1.4.2 金基修饰电极................................................ 14
1.4.3 碳基修饰电极................................................ 15
1.4.4 铋基修饰电极................................................ 16
1.4.5 其它材料修饰电极............................................ 18
1.5 本论文的研究内容及意义 ....................................... 19
第2 章 铋复合膜修饰电极的制备及在Pb(II)检测中的应用
2.1 引言 ......................................................... 23
2.2 实验部分 ..................................................... 24
2.2.1 材料与试剂.................................................. 24
2.2.2 仪器与设备.................................................. 25
2.2.3 GR-Bi/SPE 复合材料修饰丝网印刷电极的制备 ................... 25
2.2.4 电化学检测过程.............................................. 26
2.2.5 实际样品预处理.............................................. 26
2.3 结果与讨论 ................................................... 26
2.3.1 GR-Bi/SPE 复合材料修饰丝网印刷电极的表征 ................... 26
2.3.2 GR-Bi/SPE 复合材料修饰丝网印刷电极用于Pb(II)的检测 ......... 29
2.3.3 GR-Bi/SPE 用于Pb(II)检测的实验条件优化 ..................... 30
2.3.4 GR-Bi/SPE 用于Pb(II)检测的标准曲线 ......................... 31
2.3.5 GR-Bi/SPE 的重现性和干扰实验 ............................... 32
2.3.6 实际样品测定................................................ 33
2.4 结论 ......................................................... 34
第3 章 铋纳米片修饰电极的制备及在Fe(III)检测中的应用 
3.1 引言 ......................................................... 35
3.2 实验部分 ..................................................... 36
3.2.1 材料与试剂.................................................. 36
3.2.2 仪器与设备.................................................. 36
3.2.3 BiNSs 纳米材料的制备 ....................................... 36
3.2.4 BiNSs 纳米材料修饰电极的制备 ............................... 37
3.2.5 电化学检测过程.............................................. 37
3.2.6 实际样品预处理.............................................. 38
3.3 结果与讨论 ................................................... 38
3.3.1 BiNSs 纳米材料的表征 ....................................... 38
3.3.2 BiNSs/GCE 修饰电极用于Fe(III)的检测 ........................ 39
3.3.3 BiNSs/GCE 检测Fe(III)的实验条件优化 ........................ 41
3.3.4 BiNSs/GCE 检测Fe(III)的标准曲线和检出限 .................... 44
3.3.5 BiNSs/GCE 检测Fe(III)的重现性、重复性和选择性 .............. 46
3.3.6 实际样品测定................................................ 46
3.4 结论
第4 章 铋棒修饰电极的制备及在Fe(III)检测中的应用 ................. 49
4.1 引言 ......................................................... 49
4.2 实验部分 ..................................................... 49
4.2.1 材料与试剂.................................................. 49
4.2.2 仪器与设备.................................................. 50
4.2.3 BiMRs 材料的制备 ........................................... 50
4.2.4 BiMRs 纳米材料修饰电极的制备 ............................... 51
4.2.5 电化学检测Fe(III)过程 ...................................... 51
4.2.6 实际样品预处理.............................................. 51
4.3 结果与讨论 ................................................... 51
4.3.1 BiMRs 纳米材料的表征 ....................................... 51
4.3.2 不同形貌的铋材料对Fe(III)的响应比较 ........................ 54
4.3.3 支持电解质的影响............................................ 55
4.3.4 BiMRs/GCE 检测Fe(III)的标准曲线和检出限 .................... 55
4.3.5 实际样品测定................................................ 56
4.4 结论 ......................................................... 57
第5 章 铋棒修饰电极用于河水中不同形态Fe 检测和流域分布研究
5.1 引言 ......................................................... 59
5.2 实验部分 ..................................................... 60
5.2.1 材料与试剂.................................................. 60
5.2.2 仪器与设备.................................................. 60
5.2.3 样品的采集与处理............................................ 61
5.2.4 电化学检测过程.............................................. 62
5.3 结果与讨论 ................................................... 62
5.3.1 方法准确性验证.............................................. 62
5.3.2 水样的理化参数和不同形态铁浓度分析.......................... 63
5.3.3 不同形态铁的浓度分布特征分析................................ 64
5.3.4 不同形态铁与水样理化参数相关性分析.......................... 67
5.4 结论 ......................................................... 67
第6 章 金修饰电极用于海水中不同形态Cu 检测和定点分析研究 
6.1 引言 ......................................................... 69
6.2 实验部分 ..................................................... 70
6.2.1 材料与试剂.................................................. 70
6.2.2 仪器与设备.................................................. 70
6.2.3 样品的采集与处理............................................ 71
6.2.4 电化学检测过程.............................................. 72
6.3 结果与讨论 ................................................... 72
铋基电极的构建及在海岸带水体金属检测中的应用
XII
6.3.1 海水中不同形态铜............................................ 72
6.3.2 方法准确性研究.............................................. 73
6.3.3 方法稳定性研究.............................................. 74
6.3.4 海水中不同形态铜的实际检测分析.............................. 75
6.3.5 不同形态铜与各环境理化参数之间的关系........................ 79
6.4 结论 ......................................................... 80
第7 章 基于刻蚀ITO 的金铋复合修饰电极的构建及在Fe 形态分析
中的应用 ......................................................... 81
7.1 引言 ......................................................... 81
7.2 实验部分 ..................................................... 82
7.2.1 材料与试剂.................................................. 82
7.2.2 仪器与设备.................................................. 83
7.2.3 铋基ITO 修饰电极的制备 ..................................... 83
7.2.4 电化学检测过程.............................................. 83
7.2.5 实际样品的采集和预处理...................................... 84
7.3 结果与讨论 ................................................... 84
7.3.1 材料的选择及Fe(III)的检测 .................................. 84
7.3.2 ITO 电极的表征 ............................................. 85
7.3.3 Au-Bi/ITO 检测Fe(III)的实验条件优化 ........................ 88
7.3.4 Au-Bi/ITO 检测Fe(III)的标准曲线和检出限 .................... 91
7.3.5 实际样品测定................................................ 92
7.4 结论 ......................................................... 93
第8 章 结论与展望 
8.1 结论 ......................................................... 95
8.2 展望 ......................................................... 97
参考文献 ......................................................... 99
致 谢 ........................................................... 119

页数1-123
语种中文
文献类型学位论文
条目标识符http://ir.yic.ac.cn/handle/133337/24011
专题中科院烟台海岸带研究所知识产出
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胡雪萍. 铋基电极的构建及在海岸带水体金属检测中的应用[D]. 中国科学院烟台海岸带研究所. 中国科学院大学,2018.
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