Abstract Capacitive deionization (CDI) is an alternative water desalination technology, which was investigated extensively in the last decade. The choice of electrodes' materials plays a major role in the electrosorption performance, affecting the whole desalination process. Graphene-based nanostructures in various types were extensively studied owing to their superior inherent physico-chemical properties. Whereas excellent electrosorption performance was reported – expressed in terms of salt adsorption capacity (SAC) or average salt adsorption rate (ASAR) – the cost-benefit of graphene-based electrodes, considering total production cost and much lower price of commercial activated carbon, is still controversial. Here, we explore partially exfoliated thermally reduced graphene oxide (GO) – denoted as PE-rGO – prepared by scalable low-temperature thermal exfoliation of GO under air atmosphere. PE-rGO displays a “paper-like” structure with nanoscale pores. By the construction of a lab-scale system, a few grams of product were produced in one batch. A PE-rGO electrode assembled in membrane-CDI three-electrode configuration showed moderate to high SAC of around 13 mg/g under potential window of 0–550 mV versus Ref. electrode in 2000 ppm NaCl solution. However, the energy consumption was shown to be nearly constant with increasing ASAR. This has significant implications for the energy consumption and the projected capital costs.

中文翻译：

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热还原氧化石墨烯作为 CDI 工艺的电极：性能和可扩展性之间的折衷？

摘要 电容去离子（CDI）是一种替代的海水淡化技术，在过去的十年中得到了广泛的研究。电极材料的选择对电吸附性能起着重要作用，影响整个脱盐过程。各种类型的石墨烯基纳米结构由于其优越的固有物理化学性质而被广泛研究。尽管报告了优异的电吸附性能——以盐吸附容量 (SAC) 或平均盐吸附率 (ASAR) 表示——考虑到总生产成本和商业活性炭的低得多的价格，石墨烯基电极的成本效益是仍有争议。这里，我们探索了部分剥离的热还原氧化石墨烯（GO）——表示为 PE-rGO——通过在空气气氛下对 GO 进行可扩展的低温热剥离来制备。PE-rGO 显示出具有纳米级孔隙的“纸状”结构。通过构建实验室规模的系统，一批产品生产了几克产品。组装在膜-CDI 三电极配置中的 PE-rGO 电极在 0-550 mV 的电位窗口下显示出约 13 mg/g 的中至高 SAC。电极在 2000 ppm NaCl 溶液中。然而，随着 ASAR 的增加，能耗几乎保持不变。这对能源消耗和预计的资本成本有重大影响。通过构建实验室规模的系统，一批产品生产了几克产品。组装在膜-CDI 三电极配置中的 PE-rGO 电极在 0-550 mV 的电位窗口下显示出约 13 mg/g 的中至高 SAC。电极在 2000 ppm NaCl 溶液中。然而，随着 ASAR 的增加，能耗几乎保持不变。这对能源消耗和预计的资本成本有重大影响。通过构建实验室规模的系统，一批产品生产了几克产品。组装在膜-CDI 三电极配置中的 PE-rGO 电极在 0-550 mV 的电位窗口下显示出约 13 mg/g 的中至高 SAC。电极在 2000 ppm NaCl 溶液中。然而，随着 ASAR 的增加，能耗几乎保持不变。这对能源消耗和预计的资本成本有重大影响。