近年來奈米科技的進步，帶動材料科學的發展，種種優異性質材料被相繼被開發出來，其中也發展出嶄新的電吸附材料－碳氣凝膠紙。碳氣凝膠因具備有奈米尺度的細微孔洞、良好的極化能力、高的導電度性和高表面積等，其種種優異的性質適合作為電吸附材，因此有鑑於此，本研究利用碳氣膠電極電吸附水中二氯化銅，控制電壓和濃度，監測溫度、導電度、電流、總銅離子濃度、一價銅離子濃度、氯離子濃度和pH的變化，以瞭解其電吸附重金屬的行為。 研究結果發現，電吸附初期，陽極含氧官能基的氧化反應會釋出氫根離子，而到電吸附後期，陰極上的銅離子和氫根離子可能作為電子失去者，以上所述氧化還原反應的發生均會造成水體中氫根離子持續不斷的累積而導致水體pH值下降和導電度上升。電吸附結果顯示，銅離子初始濃度，對銅之去除效率影響有限，在外加電壓分別為1.2 V與1.0 V時，銅離子的去除效率分別可達99 %和95 %以上，唯達平衡之時間，隨銅離子濃度升高而所縮短。 再生實驗中以pH為3的鹽酸來清洗碳氣凝膠紙的效果最佳，且經酸洗流程後再進行pH調整為10的氫氧化鈉來進行鹼洗，以去除不利於電吸附的氫根離子，碳氣凝膠紙經以上所述再生流程後，即可獲得與新的碳氣凝膠紙相似的電吸附特性。 Carbon aerogel composite has good properties such as nanopores, high electrical conductivity, and high surface area; therefore, carbon aerogel composite is suitable for electrosorption. In this study, carbon aerogel composite was used to electro-adsorb CuCl2 in pure water. The influences of applied voltage and copper concentration on the electrosoprtion of CuCl2 were investigated. Temperature, conductivity, current, pH, and concentrations of total copper, cuprous and chloride ions were monitored. The result showed that, in the initial stage of electrosorption, hydrogen ions were released from the anode due to the oxidation of oxygen-containing functional groups on the carbon aerogel composite. Later, hydrogen ion may be released from cathode due to the reduction reactions from the functional groups on the carbon aerogel composite. Both reactions resulted in accumulation of hydrogen ions; as the consequence, the solution pH decreased and the conductivity increased. The removal efficiencies were similar (>95%) when the applied voltages were 1.0 V and 1.2 V. However, as the concentration of copper increased, the electrosorption equilibrium time decreased. It was also found that washing the carbon aerogel composite by the HCl solution of pH 3 has the best regenerate efficiency. Further washing by NaOH of pH 10 can wash out the free hydrogen ions in the pores and the washed carbon aerogel composite showed similar electrosoprtion behaviors to a new one.
