二氧化矽修飾活性碳應用於電容去離子技術

Silica-decorated Activated Carbon for Capacitive Deionization

劉易儒(Yi-Ru Liu)

指導教授 ： 林正嵐

共同指導教授 ： 彭晴玉(Ching-Yu Peng)

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2022年)

https://doi.org/10.6846/TKU.2022.00116

摘要

電容去離子技術(capacitive deionization, CDI)可透過施加電位差於具有大比電容值(specific capacitance)的電極，從水溶液中去除離子，為深具潛力之低耗能、低成本之脫鹽技術。本研究以溶膠/凝膠法製備二氧化矽(silica, SiO2)顆粒，與活性碳(activated carbon, AC)混合成為具有不同SiO2/DAC比例之複合材料電極應用於電容去離子技術中，和一般活性碳比較其效能，並找出SiO2/DAC複合材料電極應用於電容去離子之最佳比例。
研究發現不同重量百分比之二氧化矽/活性碳複合材料中，複合材料之比表面積較一般活性碳大，電化學分析中得知二氧化矽比例與比電容成正相關，但與電化學阻抗成負相關，不利於離子在電極上進行傳導，因此需要透過電容去離子實驗找出最佳二氧化矽/活性碳重量百分比例。
比較一般活性碳與不同重量百分比之二氧化矽/活性碳複合材料之電容去離子性能，在複合材料為(SiO2)15DAC85 時，其具有最大之去除效率(34.8 %)，以及最大之離子電吸附容量264.3 μmol Na+/g以及 230.45μmol Cl-/g，而當二氧化矽比例繼續提升，其去除效率與電吸附容量則急遽下降，表明二氧化矽/活性碳有最佳之結合比例。

關鍵字

電容去離子 ； 二氧化矽 ； 活性碳 ； Sol/gel合成

並列摘要

Capacitive deionization (CDI) can remove ions from aqueous solutions by applying a voltage between two electrodes with large specific capacitance, is a low-energy,low-cost desalination technology with great potential. In this study, silicon dioxide (silica,SiO2) particles were synthesis by sol/gel method ,and mixed with decorated activated carbon (DAC) to generate composite electrodes with different SiO2/DAC ratios to improve capacitive deionization efficiency , and compare its performance to general activated carbon, also find the best composite ratio of SiO2/DAC for capacitive deionization.
This study found that in the SiO2/DAC composite materials with different weight percentages, the specific surface area of the composite material is larger than that general activatd carbon, The electrochemical analysis shows that the propotion of silica is positively related to the specific capacitance, but negatively related to the electrochemical impedance. it is necessary to find the optimal weight percentage SiO2/DAC of through capacitive deionization experiments.
In comparison of the capacitance deionization performance, (SiO2)15DAC85 has the largest removal efficiency (34.8 %), and the largest electrosorption capacity was 264.3 μmol Na+/g and 230.45μmol Cl-/g.

並列關鍵字

Capacitive Deionization ； silica dioxide ； activated carbon ； sol/gel method

參考文獻

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