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水的方法，甚至可以去除一系列污染物，如重金属。这种方法的原理很简单：在高比表面积的电极上施加电压，离子被电容吸附在表面上。表面化学的修饰允许离子选择性，通过电容或法拉第效应。尽管该方法被认为(在能量和潜在的成本方面)可与替代分离方法(纳米过滤、反渗透或传统蒸馏)相媲美，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--迄今仍未得到回答。从科学上讲，该项目的关键初始任务将是探索如何选择性地去除可溶物质以及回收的限制(包括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，或金属的法拉第(电沉积)去除，再加上电容式反离子去除。较长期的目标将是从基本的电化学角度确定CDI方法的限制。

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.