Activated carbon from banana trunk fiber as an effective electrode material for desalination via capacitive deionization

Many studies have recently shown that capacitive deionisation (CDI) technology has great potential in desalination. In CDI, the electrode material is one of the important factors contributing to the desalination efficiency of this technology. Additionally, the use of biomass waste-based products could be attractive as a supplementary sustainable material supply. In this study, biochar was fabricated from banana trunk fibres and activated by KOH, which was then utilised as electrode for the desalination process. The banana trunk activated carbon was characterised using X‐ray diffraction (XRD), Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM), and Brunauer–Emmett–Teller (BET). The electrochemical properties were investigated using cyclic voltammetry (CV) and Galvanostatic Charge/Discharge (GCD). The banana trunk activated carbon calcined at 700°C and modified with 3%CB exhibited remarkable specific capacitance, conductivity, and durability; thus, it would be employed as electrode for the desalination process. The maximum salt adsorption capacity was 17.5 mg.g−1 at 1.2 V, which can be enhanced to 24.53 mg.g−1 at 1.6 V. Banana trunk fibres were proven to be an effective, cheap, and sustainable source for the fabrication of carbonaceous electrode materials which can be utilised in various electrochemical applications.