A New Technique for Carbon Layer Formation for Application in Capacitive Deionization

This paper presents a novel technique for producing a CDI electrode through a straightforward process of converting activated carbon powder into a functioning stack for application in desalination. The foundation for this new technique is implementing the carbon layer via a novel carbon-on-mesh (CM) structure. This work elaborates on the CM formation process through flocculated carbon and filtration using the mesh as the filter medium. Alum-induced sweep flocculation, from a starting pH of 4.1 resulted in a good distribution of the PTFE binder to the carbon, as indicated by electron microscopy, producing a CM layer of 300 μm carbon thickness. Three electrode assemblies were handcrafted to demonstrate repeatability, comprising N = 20 cells. The stack’s performance was measured at 0.13, 0.13, and 0.11 mmol g − 1 adsorption capacity based on NaCl outlet concentration. The average salt adsorption rate (ASAR) performance was 0.74, 0.73 and 0.70 mg g − 1 min − 1 at 1.2 V (300 s adsorb and 300 s zero-volt desorb). These results align with other benchmark studies indicating that this technique is effective at recreating a carbon stack that has good electrosorption characteristics. This study demonstrates that a CDI stack can be made using common laboratory reagents and equipment thus reducing the barrier to entry for the technology. This paper presents a novel technique for producing a CDI electrode through a straightforward process of converting activated carbon powder into a functioning stack for application in desalination. Three electrodes were produced each containing 20 cells. The average salt adsorption rate (ASAR) performance was 0.74, 0.73 and 0.70 mg per gram per minute at 1.2 V respectively. This study demonstrates that a CDI stack can be made using common laboratory reagents and equipment thus reducing the barrier to entry for the technology.