Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, 487372, Singapore.
Nanoscale. 2017 Sep 14;9(35):13305-13312. doi: 10.1039/c7nr03579a.
Desalination is a sustainable process that removes sodium and chloride ions from seawater. Herein, we demonstrate a faradaic mechanism to promote the capacity of capacitive deionization in highly concentrated salt water via an electrochemical deionization device. In this system, ion removal is achieved by the faradaic mechanism via a constant current operation mode, which is improved based on the constant voltage operation mode used in the conventional CDI operation. Benefiting from the high capacity and excellent rate performance of Prussian blue as an active electrochemical reaction material, the designed unit has revealed a superior removal capacity with an ultrafast ion removal rate. A high removal capacity of 101.7 mg g has been obtained with proper flow rate and current density. To further improve the performance of the EDI, a reduced graphene oxide with nanopores and Prussian blue composite has been synthesized. The PB@NPG has demonstrated a high salt removal capacity of 120.0 mg g at 1 C with an energy consumption of 6.76 kT per ion removed, which is much lower than most CDI methods. A particularly high rate performance of 0.5430 mg g s has been achieved at 40 C. The faradaic mechanism promoted EDI has provided a new insight into the design and selection of host materials for highly concentrated salt water desalination.
海水淡化是一种可持续的过程，可以去除海水中的钠离子和氯离子。在此，我们通过电化学脱盐装置展示了一种促进高浓度盐水电容去离子化容量的法拉第机制。在该系统中，通过恒流操作模式实现离子去除，该模式基于传统 CDI 操作中的恒压操作模式进行改进。得益于普鲁士蓝作为一种活性电化学反应材料的高容量和优异的倍率性能，所设计的单元具有优异的去除容量和超快的离子去除率。在适当的流速和电流密度下，获得了 101.7 mg g 的高去除容量。为了进一步提高 EDI 的性能，合成了具有纳米孔和普鲁士蓝复合材料的还原氧化石墨烯。PB@NPG 在 1 C 时表现出 120.0 mg g 的高盐去除容量，去除每个离子的能耗为 6.76 kT，远低于大多数 CDI 方法。在 40°C 时，实现了特别高的倍率性能，为 0.5430 mg g s。促进 EDI 的法拉第机制为高浓度盐水淡化的宿主材料的设计和选择提供了新的见解。
