【作者】 赵青；

【导师】 姚秉华；

【作者基本信息】 西安理工大学 ， 环境工程， 2005， 硕士

【摘要】 酚类化合物是橡胶、染料、医药和石油等行业排放废水中的主要有机污染物之一,目前对酚的检测仅限于挥发酚的总量检测,对于具体酚类污染物的含量分析是水质检测方法研究的一个重要内容。本文应用碳纳米管修饰电极,针对两类代表性酚类污染物—苯二酚和硝基酚,利用三电极电化学系统,进行了修饰电极电化学检测方法的研究,探讨了电极制备方法,系统研究了修饰电极对酚类化合物电催化作用机理,取得了以下研究结果: 1、利用多壁碳纳米管（MWNT）优越的物化性质,获得MWNT/GC修饰电极的最佳制备方法:以N,N-二甲基甲酰胺（DMF）为分散介质,将经酸化处理后的MWNT超声分散于DMF中,获得分散液。然后将分散液涂敷于电极表面,制成修饰电极。在pH5.6～7.0的磷酸盐缓冲溶液中,该电极能催化对苯二酚和对硝基苯酚的电化学氧化。 2、在0.2mol·dm^-3磷酸盐缓冲溶液（pH 5.5）中,对苯二酚在MWNT修饰电极上有一灵敏的氧化峰,其峰电位为0.068V（vs.SCE）,氧化峰电流与对苯二酚的浓度在2.0×10^-6～2.6×10^-3mol·dm^-3之间有良好的线性关系:i_p（μA）=60.0+6.2×10⁴c（r=0.993）。对苯二酚的检出限为1.0×10^-6mol·dm^-3。以浓度为2.0×10^-4mol·dm^-3对苯二酚为试样进行干扰试验（误差在±5%之间）,结果表明:20倍于对苯二酚的Cu²⁺,更多还原

【Abstract】 Phenol is one of the organic pollutants in the wastewater from rubber, dyes, medicine and petroleum et al. manufactures. At the present, phenol test is restricted to the total detection of volatile phenol. Therefore, it is important to establish quantitative determination methods for the specific phenol pollutant. In this dissertation, two kinds of representative phenols as model reactant: p-benzenediol and p-nitrophenol are studied by the electrochemistry examination on the carbon nanotubes modified electrodes. It is discussed that the preparation method of the electrodes and the optimal detection conditions. The electrocatalytic mechanism of the modified electrodes to phenols is studied systematically. The below conclusions are obtained:1. Using the superior physicochemical properties of the multi-walled carbon nanotubes （MWNT）, the best preparation method of modified electrodes is obtained. Acid-treated MWNTs are dispersed in DMF by supersonic and then immobilized on the GC electrodes surface to form a modified electrode. In the pH 5.5-7.0 phosphate buffer solution, the electrochemistry oxidation process on the modified electrodes of p-benzenediol and p-nitrophenol can be accelerated.2. In the 0.2 mol-dm"3 pH 5.5 phosphate buffer solution, there is a keen oxidation peak of the p-benzenediol decorates on the modified electrodes. The peak potential is -0.068V. The peak current is linear to the concentration of p-benzenediol in the range of 1.6×10^-6 to2.6xlO’3 mol-dm’3. ip C/uA) = 60.0+6.2xl04c O= 0.993) . The detection limit is l.OxlCT mol-dm"3. With a 2.0xl0"4 mol-dm’3 concentration of p-benzenediol, the disturb examination （error between ±5%） is carried on. The result indicates that twenty-fold greater amount of Cu2+, Pb2+, Hg2+, Fe2+, Al3+, Zn2+, Cl", NO3" and the phenol, one-fold greater amount of o-benzenediol do not interfere with the determination of p-benzenediol. The relative standard deviation of 20 parallel determinations （RSD） is 1.5%.3. In the pH7 phosphate buffer solution, there is a pair of oxidation-reduction peak of p-nitrophenol （Eap =-0.049v; Ecp = -0.270V） between -0.6 and 0.6V on the MWNTs modified electrodes. The peak current and scanning velocity is direct ratio. The peak current is linear to the concentration of p-nitrophenol in the range of 4.0xl0"6 to 5.0xl0"4 mol-dm"3.tp (/（A） =51.0+1.29xl05c （r=0.999）, The detection limit is 2.0xl0"6 mol-dm"3. With a 2.0xl0"4 mol-dm’3 concentration of p-nitrophenol, the disturb examination （error between ±5%） is carried on. The result indicates that ten-fold greater amount of Cu2+, Pb2+, Hg2+, Fe2+, Al3+. Zn2+, Cl", NO3" and the phenol, one-fold greater amount of o-nitrophenol and 2,4-dinitrophenol did not interfere with the determination of p-nitrophenol. The relative standard deviation of 5 parallel determinations （RSD） is 4.8%.4. The results indicated that under the chosen conditions, the reversibility of cyclic voltammetric response of p-nitrophenol was better, but the invertibility of p-benzenediol was worse. When the scanning speed changes between 10 210mV/s, no matter p-benzenediol or p-nitrophenol, their oxidation peak current all has the direct ratio with square root of the scanning speed. It is indicated that the oxidation-reduction processes of two phenols on the modified electrodes mainly are controlled by the proliferation.5. Taking the newly method to detect the p-benzenediol and p-nitrophenol in the simulation waste water, the recovery rate separately is 96.7%¹05% and 98%¹02%. It is concluded that the examination methods of p-benzenediol and p-nitrophenol on the MWNTs modified electrodes are two simple, fast and keen methods.更多还原