Development and Characterization of κ-Carrageenan and Boron Nitride Nanoparticle Membranes for Improved Ionic Conductivity in Fuel Cells

The development of alga-based biodegradable membranes represents a significant advancement in fuel cell technology, aligning with the need for sustainable material solutions. In a significant advancement for sustainable energy technologies, we have developed a novel biodegradable κ-carrageenan (KC) and boron nitride (BN) nanoparticle membrane, optimized with ammonium sulfate (NHS). This study employed a set of characterization techniques, including thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), where thermal anomalies were observed in the membranes around 160 °C and 300 °C as products of chemical decomposition. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) revealed the phases corresponding to the different precursors, whose value in the EDS measurements reached a maximum in the KC/BN/NHS5% membrane at 2.31 keV. In terms of the mechanical properties (MPs), a maximum tensile stress value of 10.96 MPa was achieved for the KC/BN sample. Using Fourier transform infrared spectroscopy (FTIR), the physicochemical properties of the membranes were evaluated. Our findings reveal that the KC/BN/NHS1% membrane achieves an exceptional ionic conductivity of 7.82 × 10−5 S/cm, as determined by impedance spectroscopy (IS). The properties of the developed membrane composite suggest possible broader applications in areas such as sensor technology, water purification, and ecologically responsive packaging. This underscores the role of nanotechnology in enhancing the functional versatility and sustainability of energy materials, propelling the development of green technology solutions.