Examination of the double-layer capacitance of an high specific-area C-cloth electrode as titrated from acidic to alkaline pHs
Examination of the double-layer capacitance of an high specific-area C-cloth electrode as titrated from acidic to alkaline pHs
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DOI：
10.1016/j.electacta.2006.04.045
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发表时间：
2006-09-15
影响因子：
6.6
通讯作者：
Conway, Brian E.
中科院分区：
文献类型：
--
作者：
Andreas, Heather A.;Conway, Brian E.
进行C-布电化学电容器电极的界面电容的滴定，以评估在0-14的范围内作为水性电解质的pH的函数的循环伏安法（CV）响应的目的。当pH从0（H2SO 4水溶液）增加到pH 11的碱性逐渐增加（NaOH）溶液时，可以看到电容损失30%，部分归因于基于表面醌基氧化/还原的准电容峰的消失。当pH增加到11以上时，电容增加约100。20%，因为其他表面官能团（吡喃酮衍生物和另一种未知物质）在碱性溶液中被活化。当C-布从pH 14滴定到2时，CV电流曲线收缩（伴随着电荷存储容量的降低）。然而，在电解质pH值低于ca. 2时，醌官能团被活化，电荷存储容量增加约。比初始值高出30%。有人发现，在pH 14的电解质中的CV电流响应较小时，滴定是碱引发的，而不是酸引发的，由于需要一个活化步骤，使吡喃酮官能团在碱性溶液中的活性。(c)2006爱思唯尔有限公司保留所有权利。
The titration of the interfacial capacitance of a C-cloth electrochemical capacitor electrode was undertaken for the purpose of evaluating the cyclic voltammetry (CV) responses as a function of the pH of an aqueous electrolyte over the range of 0-14. As the pH was increased from 0 (aqueous H2SO4) to a progressively more alkaline (NaOH) solution of pH 11, a 30% loss in capacitance is seen, partly attributable to the disappearance of the pseudocapacitive peaks based on the oxidation/reduction of the surface quinone groups. As the pH is increased above 11, the capacitance increases ca. 20%, as other surface functionalities (a pyrone derivative and another unknown species) become activated in alkaline solution. When the C-cloth is titrated from pHs of 14 to 2, the CV current profile shrinks (with a concomitant decrease in charge-storage capacity). However, at electrolyte pHs below ca. 2, the quinone functionalities are activated and the charge-storage capacity increases ca. 30% above the initial value. It was found that the CV current responses in pH 14 electrolytes are smaller when the titration is base-initiated, rather than acid-initiated, due to an activation step required to make the pyrone functionalities active in alkaline solution. (c) 2006 Elsevier Ltd. All rights reserved.