多孔钛基掺锑二氧化锡管式膜电极的制备及其催化性能研究
发布时间：2018-10-30 12:11
【摘要】：电催化氧化技术以其环境兼容性和环境友好性等特点引起环境学界广泛关注。开发电催化活性高、使用寿命长的高性能阳极材料是学者研究的热点。本文从制备方法和改变基体材料结构两个方面入手,旨在设计出合理的反应器、制备出一种兼具电催化活性和膜过滤性能的多孔Ti/Sb-SnO2管式膜电极,以期提高电极性能和电荷利用率,从而能够高效地催化降解水中污染物。以钛滤管代替传统钛板为基体,采用不同的制备方法得到了具有不同表面微观结构的多孔Ti/Sb-SnO2管式膜电极。SEM、孔径分布测试技术表征结果显示,采用Pechini法和超声浸没法结合制备所得的电极晶粒尺寸较小,通过多次超声浸没热分解过程可以显著改善多孔电极内部的孔径分布,平均孔径从2.607μm减小为2.278μm,具有较大的电化学活性表面。LSV测试表明,采用Pechini法和超声浸没法结合制备所得的管状多孔Ti/Sb-SnO2电极在酸性、中性、碱性三种介质中的析氧电位分别为2.02V、2.01V、1.10V。溶液的pH值对电极的析氧电位影响较大,在碱性条件下的析氧电位明显劣于酸性条件。而溶胶凝胶法制备所得电极在0.5 mol/L Na2SO4溶液中析氧电位仅为1.44V。为探究制备电极是否具有电催化氧化和膜过滤协同作用,应用同一电极在相同电解条件下分别在普通装置和工艺组合装置中处理初始浓度为100mg/L的吡啶模拟废水,结果表明它们对毗啶去除率分别是51.96%和69.89%,通过计算电流瞬时效率,后者的电荷利用率高。考察了不同初始吡啶浓度、电解质浓度、电流密度、初始pH值对吡啶去除效果的影响来探究制备电极电催化性能。在电解质浓度(无水硫酸钠)10.0 g/L、电流密度30 mA/cm2、pH=3的最优参数条件,100mg/L吡啶废水降解处理180min的去除率达100%。从UV、HPLC和IC来分析水样得出,管式多孔Ti/Sb-SnO2阳极电催化氧化降解吡啶的过程对其中间产物也有催化氧化效果,降解过程中会产生甲酸和乙酸这种小分子有机酸,还检测到有硝酸根离子和亚硝酸根离子生成。可以推测吡啶是在管式多孔Ti/Sb-SnO2阳极表面断了C-N键使得吡啶开环然后利于后续降解效果。
[Abstract]:Electrocatalytic oxidation (EO) technology has attracted wide attention in the field of environment because of its environmental compatibility and environmental friendliness. The development of high performance anode materials with high electrocatalytic activity and long service life is a hot research topic. The purpose of this paper is to design a reasonable reactor to prepare a porous Ti/Sb-SnO2 tubular membrane electrode with both electrocatalytic activity and membrane filtration performance. In order to improve the electrode performance and charge utilization, it can efficiently catalyze the degradation of pollutants in water. Porous Ti/Sb-SnO2 tubular membrane electrode with different surface microstructure was obtained by using titanium filter tube instead of traditional titanium plate as substrate. The SEM, pore size distribution was characterized by SEM, pore size distribution technique. The grain size of the electrode which could not be prepared by Pechini method and ultrasonic immersion was small. The pore size distribution in porous electrode could be significantly improved by multiple ultrasonic immersion thermal decomposition process, and the average pore size was reduced from 2.607 渭 m to 2.278 渭 m. The results of LSV test showed that the oxygen evolution potential of tubular porous Ti/Sb-SnO2 electrode in acidic, neutral and alkaline media was 2.02V ~ (2.01V), respectively, which could not be prepared by Pechini and ultrasonic immersion, and the results showed that the oxygen evolution potential of tubular porous Ti/Sb-SnO2 electrode was 2.02V ~ (-1) V in acidic, neutral and alkaline media. 1.10V. The pH value of the solution has a great influence on the oxygen evolution potential of the electrode, and the oxygen evolution potential in the alkaline condition is obviously inferior to that in the acidic condition. However, the oxygen evolution potential of the electrode prepared by sol-gel method is only 1.44 V in 0.5 mol/L Na2SO4 solution. In order to investigate whether the electrode has synergistic effect of electrocatalytic oxidation and membrane filtration, the pyridine simulated wastewater with initial concentration of 100mg/L was treated with the same electrode under the same electrolysis condition in the common plant and the process combination device. The results show that the removal rates of pyridine are 51.96% and 69.89% respectively. The charge efficiency of the latter is high by calculating the instantaneous efficiency of the current. The effects of different initial concentration of pyridine, electrolyte concentration, current density and initial pH value on the removal efficiency of pyridine were investigated to explore the electrocatalytic performance of the prepared electrode. When the electrolyte concentration (anhydrous sodium sulfate) is 10.0 g / L and the current density is 30 mA/cm2,pH=3, the removal rate of 180min from 100mg/L pyridine wastewater is 100%. From the analysis of water samples by UV,HPLC and IC, it is concluded that the process of electrocatalytic oxidation of pyridine by tubular porous Ti/Sb-SnO2 anode also has catalytic oxidation effect on its intermediate products, resulting in the formation of small organic acids, such as formic acid and acetic acid, during the degradation process. The formation of nitrate ion and nitrite ion was also detected. It can be inferred that pyridine breaks the C-N bond on the surface of tubular porous Ti/Sb-SnO2 anode and makes the pyridine ring open and facilitate the subsequent degradation.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O646.54;X703
[Abstract]:Electrocatalytic oxidation (EO) technology has attracted wide attention in the field of environment because of its environmental compatibility and environmental friendliness. The development of high performance anode materials with high electrocatalytic activity and long service life is a hot research topic. The purpose of this paper is to design a reasonable reactor to prepare a porous Ti/Sb-SnO2 tubular membrane electrode with both electrocatalytic activity and membrane filtration performance. In order to improve the electrode performance and charge utilization, it can efficiently catalyze the degradation of pollutants in water. Porous Ti/Sb-SnO2 tubular membrane electrode with different surface microstructure was obtained by using titanium filter tube instead of traditional titanium plate as substrate. The SEM, pore size distribution was characterized by SEM, pore size distribution technique. The grain size of the electrode which could not be prepared by Pechini method and ultrasonic immersion was small. The pore size distribution in porous electrode could be significantly improved by multiple ultrasonic immersion thermal decomposition process, and the average pore size was reduced from 2.607 渭 m to 2.278 渭 m. The results of LSV test showed that the oxygen evolution potential of tubular porous Ti/Sb-SnO2 electrode in acidic, neutral and alkaline media was 2.02V ~ (2.01V), respectively, which could not be prepared by Pechini and ultrasonic immersion, and the results showed that the oxygen evolution potential of tubular porous Ti/Sb-SnO2 electrode was 2.02V ~ (-1) V in acidic, neutral and alkaline media. 1.10V. The pH value of the solution has a great influence on the oxygen evolution potential of the electrode, and the oxygen evolution potential in the alkaline condition is obviously inferior to that in the acidic condition. However, the oxygen evolution potential of the electrode prepared by sol-gel method is only 1.44 V in 0.5 mol/L Na2SO4 solution. In order to investigate whether the electrode has synergistic effect of electrocatalytic oxidation and membrane filtration, the pyridine simulated wastewater with initial concentration of 100mg/L was treated with the same electrode under the same electrolysis condition in the common plant and the process combination device. The results show that the removal rates of pyridine are 51.96% and 69.89% respectively. The charge efficiency of the latter is high by calculating the instantaneous efficiency of the current. The effects of different initial concentration of pyridine, electrolyte concentration, current density and initial pH value on the removal efficiency of pyridine were investigated to explore the electrocatalytic performance of the prepared electrode. When the electrolyte concentration (anhydrous sodium sulfate) is 10.0 g / L and the current density is 30 mA/cm2,pH=3, the removal rate of 180min from 100mg/L pyridine wastewater is 100%. From the analysis of water samples by UV,HPLC and IC, it is concluded that the process of electrocatalytic oxidation of pyridine by tubular porous Ti/Sb-SnO2 anode also has catalytic oxidation effect on its intermediate products, resulting in the formation of small organic acids, such as formic acid and acetic acid, during the degradation process. The formation of nitrate ion and nitrite ion was also detected. It can be inferred that pyridine breaks the C-N bond on the surface of tubular porous Ti/Sb-SnO2 anode and makes the pyridine ring open and facilitate the subsequent degradation.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O646.54;X703
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