Selective Metal Removal with Capacitive De-ionisation

电容去离子（CDI）已经成为一种很有前途的淡化海水的方法，并且确实可以去除重金属等一系列污染物。该方法的原理很简单：在高表面积电极上施加电压，离子被“电容性”吸附在表面上。通过电容效应或法拉第效应，表面化学修饰允许离子选择性。尽管该方法被认为与其他分离方法（纳米过滤、反渗透或传统蒸馏）（在能量和潜在成本方面）相当，但许多潜在的科学问题——关于多孔电极内形成的结构和该方法的理论限制——迄今仍未得到解答。从科学上讲，这个项目的关键初始任务将是探索如何选择性地去除可溶性物种以及恢复的限制（高浓度和低浓度限制）。要采取的策略将包括纯电容性金属去除，或法拉第（电沉积）去除金属，加上电容性反离子去除。长期目标将是从基本电化学的角度确定CDI方法的局限性。

Capacitive deionisation (CDI) has emerged as a promising way to desalinate water, and indeed remove a range of pollutants such as heavy metals. The principle of the method is simple: a voltage is applied to high surface area electrodes, and ions are adsorbed "capacitively" on the surfaces. Modification of surface chemistry allows for ion-selectivity, through either capacitive or Faradaic effects. Although the method is believed to be comparable (in energy, and potentially, cost terms) to alternative separation methods (nano-filtration, reverse osmosis or traditional distillation), many underlying scientific questions - about the structures formed within the porous electrodes and the theoretical limits of the approach - are unanswered to date.Scientifically, the key initial task for this project will be to explore how soluble species can be removed selectively and the limits on the recovery (both high and low concentrations limits). Strategies to be pursued will involve purely capacitive metal removal, or Faradaic (electrodeposition) removal of metals, coupled with capacitive counter-ion removal. The longer-term goals will be to establish the limits of the CDI approach from a fundamental electrochemical perspective.