Tunning the surface chemistry of commercial activated carbon felt for improved asymmetric capacitive deionization

• Grant number: 23/15868-8
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Effective date (Start): March 25, 2024
• Effective date (End): July 24, 2024
• Field of knowledge: Engineering - Chemical Engineering - Chemical Process Industries
• Principal Investigator: Luis Augusto Martins Ruotolo
• Grantee: Bruno Gomes Martins Alves
• Supervisor: Andrea Lamberti
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Research place: Politecnico di Torino, Italy
• Associated to the scholarship: 23/08483-2 - Development of capacitive deionization radial-flow cell for water softening, BP.IC

Abstract

The search for desalination and water softening methods has been growing exponentially over the years as potable water becomes an increasingly scarce resource worldwide. In this regard, Capacitive Deionization (CDI) technology has been receiving special attention due to its low consumption and high energy efficiency. Similar to supercapacitor technology, capacitive deionization uses reversely polarized electrodes to remove ions from an aqueous medium, which are then retained on the electric double layer (EDL) when the liquid percolates through it. With the aim of commercial viability and universal access to this technology, commercial carbon felt electrodes (CFE) from Kynol® will be used in this project. After previous tests in our research group, it was found that the potential of zero charge (Epzc) of CFE (0.05 V vs. Ag/AgCl) was very close to the short-circuit potential (E0 = 0.02 vs. Ag/AgCl), indicating that the material is adequate to be used as either cathode and anode, since co-ion repulsion is minimized. However, from an energy efficiency standpoint, it would be favorable to use materials in an asymmetric Epzc configuration, i.e., with surface charges of the same polarity as the circuit's power terminals, in order to maximize the ion electrosorption at the positive and negative electrodes. Therefore, this BEPE-funded project is expected to assist the main FAPESP project by proposing methods, in collaboration with an overseas research group with expertise in the field, to correctly modify and subsequently analyze the electrodes, making them asymmetric by adding specific functional groups to their surface.