【摘要】：在工業(yè)迅猛發(fā)展、城市化建設加速前進的當今,環(huán)境污染問題成為了被人們?nèi)諠u重視,亟需解決對象之一。其中,水環(huán)境與人類生活息息相關,其污染更被越來越多的人重視。亞硝酸根和過氧化氫是兩種在微污染水體中比較常見的物質(zhì),它們極易溶于水,然而大劑量的攝入都對人體有嚴重的毒害作用,甚至威脅生命。對此,越來越多的研究學者著眼于研究新型材料對水質(zhì)進行檢測。常見的檢測方法主要有光譜法、色譜法、化學發(fā)光法和電化學方法等,其中,電化學方法是利用化學修飾電極對水樣進行檢測,具有操作簡單、成本低廉、反應靈敏等優(yōu)點,被廣泛運用。但是,化學修飾電極的穩(wěn)定性差一直是它的缺點,因此,需要制備具有低檢測限、高穩(wěn)定性的電化學檢測電極,用來檢測微污染水。本文以FTO為基底,利用兩步電沉積法,成功制備了基于Ni、Ag和MWNTs修飾的Ni/Ag/MWNTs/FTO電極,操作簡單,且性能穩(wěn)定。研究表明,該電極對NO2-具有良好的催化氧化能力,通過其對亞硝酸根的安培響應可知,在1 μmol·L-1～0.5 mmol·L-1濃度范圍,安培響應與亞硝酸根濃度之間具有較好的線性關系,相關系數(shù)r2=0.9932,根據(jù)多次實驗得到最低檢測限為4.6×10-7mol·L-1。該電極具有較高的靈敏度和重現(xiàn)性,且對多種陰陽離子具有較好的抗干擾能力,能應用于實際樣品的檢測。在Ni/Ag/MWNTs/FTO修飾電極的基礎上,進行性能改良,以玻碳電極(GCE)為基底電極,成功制備了Cu、Ag和MWNTs修飾的Cu/Ag/MWNTs/GCE電極,性能穩(wěn)定,操作方便。該電極對N02-具有更好的催化氧化能力,檢測限達到2×10-7 mol·L-1,比Ni/Ag/MWNTs/FTO修飾電極的檢測限(4.6×10-7 mol·L-1)低了一半多。利用Cu/Ag/MWNTs/GCE修飾電極對亞硝酸根的安培檢測可知,在亞硝酸根濃度為1μmol·L-1 ～0.05 mmol·L-1范圍內(nèi),電流與亞硝酸根濃度呈現(xiàn)良好的線性關系,具有較高的靈敏度,并且對多種陰陽離子具有抗干擾能力。在研究電極對過氧化氫的檢測中,利用分步電沉積法,成功制備出了Sn/AgNWs/MWNTs修飾電極。該電極在0.001 mmol·L-1～0.1 mol·L-1濃度范圍內(nèi),其電流響應與過氧化氫濃度呈現(xiàn)良好的一次線性關系,r2=0.9960。該電極對過氧化氫具有明顯的安培響應,且對低濃度H202具有較靈敏的電流響應值,檢測限達到1.05×10-6 mol·L-1,通過考察峰電流與掃速的關系,該電極的反應過程為吸附控制。本次工作還對MWNT改性,利用水熱法成功制備出N摻雜的MWNTs,并利用電沉積,制備了N-MWNTs/AgNWs/GCE電極,該電極對過氧化氫具有較好的電化學響應,能在低濃度條件下檢測出H202,在1 μmol·L-1 ～0.08 mol·L-1 H2O2濃度范圍內(nèi),其電化學響應值與H202濃度呈良好的一次線性關系,最低檢測限達到2.74×10-7 mol·L-1。該電極對檸檬酸CA、葡萄糖和抗壞血酸等干擾物質(zhì)具有較好的抵抗能力,過氧化氫的相應電流曲線,能在干擾物質(zhì)加入后迅速恢復穩(wěn)定,且穩(wěn)定性和重現(xiàn)性良好。研究表明,本文制備的幾種電極,均具有較低的檢測限和較強的穩(wěn)定性,對多種離子或物質(zhì)具有抗干擾能力,能應用于實際微污染水樣檢測。
[Abstract]:With the rapid development of the industry and the acceleration of the construction of the urbanization, the problem of environmental pollution is becoming more and more important, and it is urgent to solve one of the objects. Among them, the water environment is closely related to human life, and its pollution is more and more attention. Nitrite and hydrogen peroxide are two more common substances in micro-polluted water. They are very soluble in water. However, large doses of hydrogen peroxide have serious toxic effects on the human body, and even threaten life. In this regard, more and more researchers have focused on the research of new materials for the detection of water quality. the common detection method mainly has the advantages of spectrum, chromatography, chemiluminescence, electrochemical method and the like, wherein the electrochemical method is used for detecting the water sample by using the chemically modified electrode, and has the advantages of simple operation, low cost, sensitive reaction and the like, and is widely applied. However, the stability difference of the chemically modified electrode has always been a disadvantage, and therefore, it is necessary to prepare an electrochemical detection electrode with a low detection limit and a high stability, for detecting the micro-polluted water. Based on FTO, the Ni/ Ag/ MWNTs/ FTO electrode modified based on Ni, Ag and MWNTs was successfully prepared by two-step electrodeposition, and the operation was simple and the performance was stable. The results show that the electrode has good catalytic oxidation ability to NO2, and it can be found that the concentration range of 1. mu.mol 路 L-1-0.5 mmol 路 L-1, the response of ampere and the concentration of nitrite have a good linear relationship, and the correlation coefficient r2 is 0.9932, The minimum detection limit of 4. 6-10-7mol 路 L-1 was obtained from a number of experiments. The electrode has high sensitivity and reproducibility, and has better anti-interference ability for a plurality of positive and negative ions, and can be applied to the detection of an actual sample. On the basis of Ni/ Ag/ MWNTs/ FTO modified electrode, the properties of Cu, Ag and MWNTs modified Cu/ Ag/ MWNTs/ GCE electrodes were successfully prepared by using glass-carbon electrode (GCE) as the base electrode. The electrode pair N02-has better catalytic oxidation capacity, the detection limit reaches 2-10-7 mol 路 L-1, and the detection limit of the electrode is less than that of the Ni/ Ag/ MWNTs/ FTO modified electrode (4. 6-10-7 mol 路 L-1). It is found that the concentration of nitrite in the range of 1. m u.mol. L-1 to 0.05 mmol 路 L-1 shows a good linear relationship with the concentration of nitrite in the range of 1. m u.mol. L-1 to 0. 05 mmol 路 L-1 by the Cu/ Ag/ MWNTs/ GCE modified electrode. Sn/ AgNWs/ MWNTs modified electrode was successfully prepared by the step-by-step electrodeposition method in the detection of hydrogen peroxide by the study electrode. The current response of the electrode in the range of 0.001 mmol 路 L -1 to 0.1 mol 路 L-1 shows a good linear relationship with the concentration of hydrogen peroxide, r2 = 0.9960. The electrode has an obvious ampere response to the hydrogen peroxide, and the low-concentration H202 has a sensitive current response value, the detection limit reaches 1. 05-10-6 mol 路 L-1, and the reaction process of the electrode is adsorption control by examining the relation between the peak current and the scanning speed. In this work, the MWNT was modified and the N-doped MWNTs was successfully prepared by the hydrothermal method, and the N-MWNTs/ AgNTs/ GCE electrode was prepared by electrodeposition. The electrode has a good electrochemical response to the hydrogen peroxide, and the H202 can be detected under the low concentration condition, and the H202 is in the range of 1umol 路 L-1-0.08mol 路 L-1H2O2. The electrochemical response has a good linear relationship with the H202 concentration, and the minimum detection limit is from 2.74 to 10-7 mol 路 L-1. The electrode has good resistance to the interfering substances such as the citric acid CA, the glucose and the ascorbic acid, and the corresponding current curve of the hydrogen peroxide can be quickly recovered and stable after the interfering substances are added, and the stability and the reproducibility are good. The research shows that several kinds of electrodes prepared in this paper have lower detection limit and strong stability, and have anti-interference ability to various ions or substances, and can be applied to the detection of actual micro-polluted water samples.
【學位授予單位】：浙江工商大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：O657.1;X832

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相關期刊論文 前1條

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本文編號：2420403