Optimizing Sustainable Energy Generation in Ethanol Fuel Cells: An Exploration of Carrageenan with TiO 2 Nanoparticles and Ni/CeO 2 Composites.

Based on the search for new biodegradable materials that are low cost and easy to synthesize by environmentally friendly methods, we report the use of carrageenan membranes (mixture of κ and λ carrageenans) with different concentrations of titanium dioxide nanoparticles (TiO 2 NPs) and Ni/CeO 2 (10 wt % Ni) for the fabrication of a novel fuel cell electrode for the oxidation of ethanol. Each membrane was characterized to determine its physicochemical properties using X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. Using impedance spectroscopy (IS), a maximum value of 2.08 × 10 -4 S/cm in ionic conductivity was found for the carrageenan nanocomposite with a concentration of 5 wt % TiO 2 NPs (CR5%). Due to its high conductivity values, the CR5% membrane was mixed with Ni/CeO 2 to prepare the working electrode for cyclic voltammetry measurements. Using a solution of 1 M ethanol and 1 M KOH, the oxidation of ethanol over CR5% + Ni/CeO 2 resulted in peak current density values at forward and reverse scan voltages of 9.52 and 12.22 mA/cm 2 , respectively. From our results, the CR5% + Ni/CeO 2 membrane proves to be more efficient in the oxidation of ethanol compared with commercially available Nafion membranes containing Ni/CeO 2 .