A novel method for metal oxide deposition on carbon aerogels with potential application in capacitive deionization of saline water
A novel method for metal oxide deposition on carbon aerogels with potential application in capacitive deionization of saline water
复制标题
DOI：
10.1016/j.electacta.2014.04.182
复制
发表时间：
2014-07
影响因子：
6.6
通讯作者：
M. C. Zafra;P. Lavela;G. Rasines;C. Macías;J. Tirado;C. Ania
中科院分区：
文献类型：
--
作者：
M. C. Zafra;P. Lavela;G. Rasines;C. Macías;J. Tirado;C. Ania
采用间苯二酚-甲醛法制备了掺杂锰、铁氧化物的碳气凝胶，并将其作为电位电极用于盐水中氯化钠的电容去离子。在超临界干燥步骤之前将含有金属前体的溶液与水凝胶混合，确保纳米金属氧化物的高度均匀分散，如通过X射线衍射和电子显微镜所测定的。XPS光谱显示活化过程后羟基和羧基的贡献增加。此外，观察到在外部颗粒表面处的增强的金属氧化。氮等温线显示，在掺杂样品的孔体积的减少归因于嵌入的纳米金属氧化物颗粒的孔结构的部分阻塞。电容值高达99 F/g和91 F/g的CAGDFeAct和CAGDMnAct分别记录通过循环伏安法。通过去离子实验证实了含铁活化气凝胶检测到的大电容。当在充电期间施加1.5 V时，记录CAGDFeAct在0.025 M NaCl溶液中的电吸附容量为0.133 mmol/g。对电极的动力学响应的研究表明CAGDMnAct的行为较差，并且与嵌入的纳米金属氧化物颗粒所施加的孔结构的部分阻塞相关。
Carbon aerogels doped with manganese or iron oxides were prepared by the resorcinol-formaldehyde method as potential electrodes for the capacitive deionization of sodium chloride from saline water. The solution containing the metal precursors was mixed with the hydrogel before the supercritical drying step ensuring a highly homogeneous dispersion of the nanometric metal oxides as determined by X-ray diffraction and electron microscopy. XPS spectra revealed the increased contribution of hydroxyl and carboxylic groups after the activation process. Also, an enhanced metal oxidation at the outer particle surface was observed. Nitrogen isotherms have revealed a decrease of the pore volume in doped samples ascribed to the partial blocking of the pore structure by the embedded nanometric metal oxide particles.Capacitance values as large as 99 F/g and 91 F/g were respectively recorded for CAGDFeAct and CAGDMnAct by cyclic voltammetry. The large capacitance detected for the iron containing activated aerogel was confirmed by deionization experiments. An electrosorption capacity of 0.133 mmol/g was recorded for CAGDFeAct in a 0.025 M NaCl solution when 1.5 V were applied during the charge period. The study of the kinetic response of the electrodes showed a poor behavior for CAGDMnAct and was correlated to the partial blocking of pore structure exerted by the embedded nanometric metal oxide particles.