Synthesis and characterization of TiO2 and Co3O4 nanoparticle-doped nanocomposite blend membranes for proton exchange membrane fuel cells

Abstract

Abstract The development of proton exchange membranes with improved physicochemical, mechanical, thermal, and electrochemical properties is essential for advancing proton exchange membrane (PEM) fuel cell technologies. In this study, nanocomposite blend membranes were fabricated using sulfonated poly(sulfone) (SPSf) and poly(styrene-co-acrylonitrile) (PSAN) at an optimal polymer ratio, with different concentrations of titanium dioxide (TiO 2 ) and cobalt oxide (Co 3 O 4 ) nanoparticles incorporated into the membrane matrix. The synthesized membranes were comprehensively evaluated in terms of sulfonation characteristics, structural and chemical properties, morphology, thermal and oxidative stability, water uptake and swelling behavior, mechanical properties, electrochemical performance, and surface topography. The SP50/PS50/T3 membrane exhibited the lowest swelling ratio of 3.22% with a water uptake capacity of 14.41%. TiO 2 -reinforced membranes generally exhibited better mechanical properties than Co 3 O 4 -reinforced membranes, with the highest tensile strength of 24 MPa and elongation at break of 2.58% obtained for SP50/PS50/T1. Co 3 O 4 incorporation improved oxidative stability, whereas TiO 2 increased weight loss, with a maximum weight loss of 22.73% for SP50/PS50/T3 after 240 h. The maximum proton conductivity values were 55.05 mS.cm − 1 for SP50/PS50/T3 and 53.53 mS.cm − 1 for SP50/PS50/C1 at 81.5 °C. Both nanoparticles improved thermal stability, and SP50/PS50/T3 exhibited suitable thermal stability for high-temperature applications. The developed nanocomposite membranes exhibited promising and tunable physicochemical, mechanical, thermal, and electrochemical properties, supporting their consideration as candidate PEM materials.