Development and Testing of Zinc Oxide Embedded Sulfonated Poly (Vinyl Alcohol) Nanocomposite Membranes for Fuel Cells

Abstract

The sol-gel technique was adopted to synthesize the zinc oxide (ZnO) nanoparticles. Nano-sized ZnO particles are embedded in-situ to the poly(vinyl alcohol) (PVA) matrix to form the nanocomposite polymeric membranes. The nanocomposite membranes were fabricated by varying concentration of ZnO nanoparticles of 2.5, 5, and 10 wt.% in the base PVA membrane matrix. The membranes were crosslinked using tetraethyl orthosilicate (TEOS) followed by hydrolysis and co-condensation. Immersion in a 2 molar sulphuric acid (H2SO4) bath produced sulfonated membranes. The membranes were characterized using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The fabricated nano-composite membranes are being evaluated for proton exchange membrane fuel cell research (PEMFC). The computed test results demonstrate that increasing the concentration of ZnO in the membrane increased the ionic exchange capacity and proton conductivity efficiency of the nano-composite membranes. The incorporation of a quantum quantity of ZnO particles in the membrane improved the presentation in terms of proton conductivity characteristics. Membranes demonstrated excellent proton conductivity (10−2 S cm−1 range) while consuming less hydrogen gas. The highest measured proton conductivity is observed for 10 wt.% ZnO embedded PVA membrane and the value is 15.321 × 10−2 S cm−1 for 100% RH. The combination of ZnO and PVA nanocomposite membrane is a novel, next-generation eco-friendly method that is economical and convenient for large-scale commercial production in fuel cell applications.