基于聚离子液体的酚类电催化研究
发布时间：2019-06-14 21:25
【摘要】：酚类化合物一直作为一类毒性强、来源广且难降解的有机污染物跻身水中优先控制污染物的黑名单,对人类身体健康与生存环境构成严重威胁。从分子结构理论可知,酚类化合物包含的苯环兀电子离域效应,使这类化合物的结构变得紧凑而牢固,化学性质稳定,难以降解。近年来,电化学处理法凭借低能耗,高效率,少污染等特点成为含酚污水处理领域的研究热点,而离子液体型导电聚合物也以其优良的电化学性能成为电催化酚类污染物常用的电极修饰材料。本论文采用电化学聚合方法,制备了聚离子液体(poly[ABMI]PF_6)和聚离子液体-纳米二氧化钛复合物(poly[ABMI]PF_6-TiO_2)两种电催化材料。采用电化学测试方法分别研究了苯酚在聚离子液体膜修饰金电极(poly[ABMI]PF_6/Au)和对苯二酚(HQ)、邻苯二酚(CC)在聚离子液体-纳米二氧化钛复合物膜修饰金电极(poly[ABMI]PF_6-TiO_2/Au)上的电化学行为。具体研究内容如下：(1)结合苯胺的可聚性与离子液体的可设计性,以咪唑、间硝基氯苄、1,4-二溴丁烷等为原料通过两步法合成功能化可聚双咪唑型离子液体(ABMI),红外光谱(IR),核磁共振(NMR) H谱和C谱等表征结果表明合成产物与目标化学物结构一致。采用计时电流法在Au电极上电聚合得到poly[ABMI]PF_6膜,结合离子液体聚合的2D和3D无因次理论模型推导出了离子液体在Au电极上的电化学聚合过程为扩散控制下的三维瞬时成核。在分散有纳米Ti02的电解液中,采用计时电流法在Au电极上电聚合得到poly[ABMI]PF_6-TiO_2复合膜,结合ABMI聚合的2D和3D无因次理论模型推导出了ABMI-TiO_2在Au电极上的电化学聚合过程同样遵循扩散控制下的三维瞬时成核理论。对比ABMI和ABMI-TiO_2循环伏安聚合过程进一步说明ABMI在Au电极上电化学聚合原理与ABMI-TiO_2在Au电极上的基本一致。通过扫描电镜(SEM)表征实现对poly[ABMI]PF_6和poly[ABMI]PF_6-TiO_2膜结构与形貌的分析。(2)应用循环伏安法技术(CV)和交流阻抗技术(EIS)对poly[ABMI]PF_6/Au电极的电化学性能进行了测试,结果表明poly[ABMI]PF_6/Au电极具有良好的电子传递能力。采用循环伏安法分别研究了poly[ABMI]PF_6/Au电极和Au电极对苯酚的电催化行为,发现相对于Au电极,poly[ABMI]PF_6/Au电极对苯酚电催化有良好的增强效果,且电极反应为1电子1质子参与的不可逆氧化反应。同时考察了缓冲液种类、pH、富集时间、扫描速率和电解液温度对苯酚的电催化氧化效果的影响,并对相关电化学参数进行了测试。苯酚氧化峰电流值与扫描速率的关系表明当扫描速率(v)在0.02～0.1 V/s范围时,苯酚在poly[ABMI]PF_6/Au电极上的电化学氧化过程是由扩散过程控制,当v在0.2～0.9 V/s范围内时,苯酚的氧化反应转由吸附过程控制；苯酚氧化峰电流值与温度(25～45℃)的关系式表明在poly[ABMI]PF_6/Au电极上,苯酚的电催化氧化反应活化能△G为30.74 kJ'mol~(-1);一定浓度范围内苯酚的氧化峰电流值与浓度之间呈良好的线性关系,表明此聚离子液体膜修饰电极能够高灵敏度检测苯酚,并有望用来对水体中的苯酚进行电化学催化氧化处理。对于拓展聚离子液体的功能及性质,构建苯酚电化学催化氧化新方法和新器件具有重要意义。(3)应用CV和EIS对poly[ABMI]PF_6-TiO_2膜的电化学性能进行了测试,结果表明poly[ABMI]PF_6-TiO_2/Au电极具有良好的电子传递能力。采用循环伏安法和差分脉冲伏安法分别研究了poly[ABMI]PF_6-TiO_2/Au电极、Au电极、poly[ABMI]PF_6/Au电极和TiO_2/Au电极对HQ和CC的电催化行为,发现相对于其他几种电极,poly[ABMI]PF_6-TiO_2/Au电极对HQ和CC的电催化氧化还原均有良好的增强效果。同时考察了缓冲液种类、pH、扫描速率和电解液温度对HQ和CC电催化性能的影响,并对相关电化学参数进行了测试。HQ和CC氧化峰电流值,还原峰电流值分别与扫描速率的关系表明HQ和CC在poly[ABMI]PF_6-TiO_2/Au电极上的电催化反应均是由扩散过程控制的2电子2质子参与的可逆电化学氧化还原过程,且修饰电极的有效面积A为0.1073 cm~2,HQ和CC扩散系数D分别为3.591×10-7 cm~2/s和1.913×10-6 cm~2/s;HQ和CC扩散系数与温度(25～45℃)的关系式表明在poly[ABMI]PF_6-TiO_2/Au电极上,HQ和CC反应活化能△G分别为49.39 kJ·mol~(-1)和34.93 kJ·mol~(-1);一定浓度范围内HQ和CC的差分脉冲伏安测试表明poly[ABMI]PF_6-TiO_2/Au电极能够高灵敏度的同时和选择性检测HQ和CC,并有望用来对水体中的HQ和CC进行电化学区分和电催化氧化还原处理。
[Abstract]:The phenolic compounds have been listed as a class of organic pollutants with strong toxicity, wide source and difficult to degrade, and the black list of the pollutants is preferentially controlled in the water, which poses a serious threat to the human health and the living environment. It is known from the molecular structure theory that the benzene ring of the phenolic compound has the electron-leaving effect, so that the structure of the compound becomes compact and firm, the chemical property is stable, and the compound is difficult to degrade. In recent years, the electrochemical treatment method has become a hot spot in the field of phenol-containing sewage treatment with low energy consumption, high efficiency and less pollution. In this paper, two kinds of electrocatalytic materials of polyionic liquid (poly[ABMI] PF _ 6) and poly ([ABMI] PF _ 6-TiO _ 2) were prepared by electrochemical polymerization. The electrochemical behavior of phenol in poly (ionic liquid membrane modified gold electrode (poly[ABMI] PF _ 6/ Au) and hydroquinone (HQ) and catechol (CC) on the modified gold electrode (poly[ABMI] PF _ 6-TiO _ 2/ Au) was studied by electrochemical test method. The specific contents of the study are as follows: (1) The properties of the polycidetomidine-type ionic liquid (ABMI) and the infrared spectrum (IR) are synthesized by a two-step method, such as detomidine, m-nitrochlorobenzene, 1,4-dibromobutane, and the like in combination with the designability of the ionic liquid of the aniline. The results of nuclear magnetic resonance (NMR) H-spectrum and C-spectrum show that the synthesis product is consistent with the target chemical structure. A poly[ABMI] PF _ 6 film was obtained by the time-current method on the Au electrode, and the three-dimensional transient nucleation of the ionic liquid under the diffusion control was derived by the 2D and 3D dimensionless theoretical models of the ionic liquid polymerization. In the electrolyte with nano Ti02, a poly[ABMI] PF _ 6-TiO _ 2 composite film was obtained by the time-current method on the Au electrode, and the two-dimensional and 3D non-dimensional theoretical model of ABMI polymerization was used to derive the three-dimensional transient nucleation theory under the diffusion control. Compared with ABMI and ABMI-TiO _ 2 cyclic voltammetry, the electrochemical polymerization principle of ABMI on Au electrode and ABMI-TiO _ 2 are consistent with that of ABMI-TiO _ 2 on Au electrode. The structure and morphology of poly[ABMI] PF _ 6 and poly[ABMI] PF _ 6-TiO _ 2 were characterized by scanning electron microscopy (SEM). (2) The electrochemical performance of poly[ABMI] PF _ 6/ Au electrode was tested by cyclic voltammetry (CV) and AC impedance (EIS). The results show that the poly[ABMI] PF _ 6/ Au electrode has good electron transfer ability. The electrocatalytic behavior of poly[ABMI] PF _ 6/ Au electrode and Au electrode on phenol was studied by cyclic voltammetry. It was found that the poly[ABMI] PF _ 6/ Au electrode had a good effect on the electrocatalysis of phenol with respect to the Au electrode, and the electrode reaction was the irreversible oxidation reaction of 1 electron 1 proton. The effect of buffer type, pH, concentration time, scanning rate and electrolyte temperature on the electrocatalytic oxidation of phenol was also investigated, and the related electrochemical parameters were tested. The relationship between the peak current value and the scanning rate of the phenol shows that when the scanning rate (v) is in the range of 0.02-0.1 V/ s, the electrochemical oxidation process of the phenol on the poly[ABMI] PF _ 6/ Au electrode is controlled by the diffusion process, and when the v is within the range of 0.2-0.9 V/ s, the oxidation reaction of the phenol is controlled by the adsorption process; The relationship between the current value of phenol oxidation peak and the temperature (25 ~ 45 鈩，
本文编号：2499708
[Abstract]:The phenolic compounds have been listed as a class of organic pollutants with strong toxicity, wide source and difficult to degrade, and the black list of the pollutants is preferentially controlled in the water, which poses a serious threat to the human health and the living environment. It is known from the molecular structure theory that the benzene ring of the phenolic compound has the electron-leaving effect, so that the structure of the compound becomes compact and firm, the chemical property is stable, and the compound is difficult to degrade. In recent years, the electrochemical treatment method has become a hot spot in the field of phenol-containing sewage treatment with low energy consumption, high efficiency and less pollution. In this paper, two kinds of electrocatalytic materials of polyionic liquid (poly[ABMI] PF _ 6) and poly ([ABMI] PF _ 6-TiO _ 2) were prepared by electrochemical polymerization. The electrochemical behavior of phenol in poly (ionic liquid membrane modified gold electrode (poly[ABMI] PF _ 6/ Au) and hydroquinone (HQ) and catechol (CC) on the modified gold electrode (poly[ABMI] PF _ 6-TiO _ 2/ Au) was studied by electrochemical test method. The specific contents of the study are as follows: (1) The properties of the polycidetomidine-type ionic liquid (ABMI) and the infrared spectrum (IR) are synthesized by a two-step method, such as detomidine, m-nitrochlorobenzene, 1,4-dibromobutane, and the like in combination with the designability of the ionic liquid of the aniline. The results of nuclear magnetic resonance (NMR) H-spectrum and C-spectrum show that the synthesis product is consistent with the target chemical structure. A poly[ABMI] PF _ 6 film was obtained by the time-current method on the Au electrode, and the three-dimensional transient nucleation of the ionic liquid under the diffusion control was derived by the 2D and 3D dimensionless theoretical models of the ionic liquid polymerization. In the electrolyte with nano Ti02, a poly[ABMI] PF _ 6-TiO _ 2 composite film was obtained by the time-current method on the Au electrode, and the two-dimensional and 3D non-dimensional theoretical model of ABMI polymerization was used to derive the three-dimensional transient nucleation theory under the diffusion control. Compared with ABMI and ABMI-TiO _ 2 cyclic voltammetry, the electrochemical polymerization principle of ABMI on Au electrode and ABMI-TiO _ 2 are consistent with that of ABMI-TiO _ 2 on Au electrode. The structure and morphology of poly[ABMI] PF _ 6 and poly[ABMI] PF _ 6-TiO _ 2 were characterized by scanning electron microscopy (SEM). (2) The electrochemical performance of poly[ABMI] PF _ 6/ Au electrode was tested by cyclic voltammetry (CV) and AC impedance (EIS). The results show that the poly[ABMI] PF _ 6/ Au electrode has good electron transfer ability. The electrocatalytic behavior of poly[ABMI] PF _ 6/ Au electrode and Au electrode on phenol was studied by cyclic voltammetry. It was found that the poly[ABMI] PF _ 6/ Au electrode had a good effect on the electrocatalysis of phenol with respect to the Au electrode, and the electrode reaction was the irreversible oxidation reaction of 1 electron 1 proton. The effect of buffer type, pH, concentration time, scanning rate and electrolyte temperature on the electrocatalytic oxidation of phenol was also investigated, and the related electrochemical parameters were tested. The relationship between the peak current value and the scanning rate of the phenol shows that when the scanning rate (v) is in the range of 0.02-0.1 V/ s, the electrochemical oxidation process of the phenol on the poly[ABMI] PF _ 6/ Au electrode is controlled by the diffusion process, and when the v is within the range of 0.2-0.9 V/ s, the oxidation reaction of the phenol is controlled by the adsorption process; The relationship between the current value of phenol oxidation peak and the temperature (25 ~ 45 鈩，
本文编号：2499708
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