多孔EDTA基碳材料的可控制备及其电化学中的应用研究

发布时间：2018-04-09 05:10

本文选题：多孔碳　切入点：EDTA　出处：《北京化工大学》2015年硕士论文

【摘要】：基于能源和资源有效利用的问题,本论文主要用一步法制出新型具有多级孔结构的碳材料HPCs,考察其在超级电容器和电吸附技术中的应用。本论文研究反应物用量,活化温度和时间等条件对HPCs的形貌和电化学性能的影响,获得目前最优化的实验条件。超级电容器和电吸附技术在原理上都采用电化学双电层储能原理,所以本论文研究了多孔碳材料HPCs在超电容和电吸附技术方面的应用。采用EDTA为碳源,活化造孔剂为KOH时合成的多孔碳EDTA基材料HPCs的比表面积最高达2185.71 m2·g-1；孔体积最高可达1.368cm3·g-.HPCs在碱性电解液(6mol·L-1KOH)中的电容值为260F·g-1；中性电解液(1mol·L-1 NaCl)中电容值为182F·g-1,充放电1000次之后电容保持率可达96%；并对其阻抗、电压降等电化学参数进行评价,结果说明HPCs是一类优良的超电容电极材料。本论文还探讨了材料的结构与电容性能之间存在的内在关系。HPCs作为电吸附电极能够实现对不同浓度NaCl溶液的处理,处理40mg·L-1NaCl溶液的电吸附容量为34.27mg·g-1；处理500mg·L-1NaCl溶液的电吸附容量为61.51mg·g-1;NaCl浓度再增加一倍时(1000mg·L-1),电吸附容量可达73.39mg@g-1；NaCl浓度变为5058mg@L-'(100mM)时,电吸附容量为87.48mg·g-1,说明EDTA基的多孔碳材料可以净化各种浓度的盐水而且其电吸附能力优于目前报道的绝大多数电极材料。而且HPCs电极物理吸附容量很小且循环使用多次后,电吸附性能几乎没有任何衰减,说明HPCs是一种极具工业应用潜力的电吸附电极。通过研究系列EDTA基碳材料的表面积,电容值和电吸附容量的变化,揭示出三者之间的内在关联,探讨影响电吸附容量的本质原因。具有最高比表面积和良好孔结构的EDTA基碳材料,其碱性和中性电解液的电容值均为最高,电吸附电容最高,表明比表面积和孔结构能够对材料的电化学特性有很大影响。探讨了HPCs电吸附电极对多种离子的混合溶液(Al3+,Fe3+,Cu2+, Mg2+, K+, Rb+或Li+)的离子选择性,它受离子的价态,水合半径和材料孔结构三种因素共同影响。HPCs具有优良的超电容和电吸附性能是由于材料多级孔结构,高比表面积,适合的孔体积,合适的孔径和石墨化程度所致。
[Abstract]:Based on the problem of efficient utilization of energy and resources, a new type of carbon material HPCswith multilevel pore structure was prepared by one-step method, and its application in supercapacitors and electrosorption technology was investigated.In this paper, the effects of the amount of reactants, activation temperature and time on the morphology and electrochemical properties of HPCs were studied, and the optimal experimental conditions were obtained.The principle of electrochemical double layer energy storage is used in supercapacitor and electroadsorption technology, so the application of porous carbon material HPCs in supercapacitor and electrosorption technology is studied in this paper.Using EDTA as carbon source,The maximum specific surface area of the porous carbon EDTA based material was 2185.71 m2 g-1 when the activated pore-making agent was KOH, the maximum pore volume was 260F g-1 in the alkaline electrolyte (6mol L -1 KOH), the capacitance value of neutral electrolyte was 182F g -1, the charge and discharge was 1000 second.The retention rate of the rear capacitance can be up to 96.The electrochemical parameters such as voltage drop are evaluated. The results show that HPCs is a kind of excellent supercapacitor electrode material.The relationship between the structure of the materials and the capacitance properties is also discussed. HPCs can be used as an electroadsorption electrode to deal with different concentrations of NaCl solution.The electrosorption capacity of 40mg L-1NaCl solution was 34.27mg g-1, and that of 500mg L-1NaCl solution was 100 mg 路L ~ (-1) when the concentration of 61.51mg g ~ (-1) L-1NaCl was doubled, and that of 500mg L-1NaCl solution could reach 73.39 mg 路g ~ (-1) 34.27mg concentration to 5058 mg 路L ~ (-1) 500mg L-1NaCl solution, and the adsorption capacity of 500mg L-1NaCl solution was 100 mg 路L ~ (-1) when the concentration of 61.51mg g ~ (-1) was increased to 100 mg 路L ~ (-1).The electrosorption capacity is 87.48mg g-1, which indicates that the porous carbon based on EDTA can purify brine of various concentrations and its adsorption capacity is better than that of most electrode materials reported at present.Moreover, the physical adsorption capacity of HPCs electrode is very small and the electrosorption performance of HPCs electrode has almost no attenuation after repeated recycling, which indicates that HPCs is a kind of electrosorption electrode with great potential for industrial application.By studying the changes of surface area, capacitance and adsorption capacity of EDTA based carbon materials, the intrinsic relationship among them is revealed, and the essential reasons influencing the adsorption capacity are discussed.For EDTA based carbon materials with the highest specific surface area and good pore structure, the capacitance of alkaline and neutral electrolytes is the highest and the capacitance of electroadsorption is the highest, indicating that the specific surface area and pore structure can greatly affect the electrochemical characteristics of the materials.The ionic selectivity of HPCs electroadsorption electrode to Al _ 3 / Fe _ 3 / Cu _ 2, Mg2, K, RB or Li was investigated.Three factors, hydration radius and pore structure, affect the excellent supercapacitor and electrosorption of HPCs due to the multilevel pore structure, high specific surface area, suitable pore volume, appropriate pore size and graphitization degree.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11;TB383.4

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