Bimetallic PdPt alloy nanoparticle-decorated track-etched polyethylene terephthalate membranes for efficient H2 separation

Abstract

To realize hydrogen economy, hydrogen purification is the primary demand, and it can be achieved using membrane technology. Additionally, embedding hydrogen-sensitive materials into the membranes could be a decent approach to reinforce the separation qualities. Bimetallic nanoparticles exhibit novel characteristics due to the synergistic impacts of the two distinct metals. Here, we report the synthesis of PdPt BNPs of around 8 nm size to decorate track-etched polyethylene terephthalate (PET) membranes for boosting hydrogen separation properties. For this purpose, the membranes were dipped into the bimetallic nanoparticle solution at different time gaps of up to 72 hours. The synthesized bimetallic nanoparticles were examined using X-ray diffraction spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy techniques, and their uniform distribution over the membranes was confirmed using field emission scanning electron microscopy (FESEM) with EDS mapping. Several approaches have been employed to increase the nanoparticles' adherence to the membrane, including UV functionalization prior to the bimetallic nanoparticle decoration and the usage of polyvinylpyrrolidone (PVP) as a binder. The engineered membranes were examined for their permeability towards H₂, N₂ and CO₂ gases. After modifications, the membranes exhibited the highest H₂ permeability of 668 128 barrer and H₂/CO₂ and H₂/N₂ selectivities of 4.18 and 4.01, respectively. In addition, we have attempted to discuss the mechanism of the improvement in the gas separation performance based on the interaction and diffusion of H₂ gas through the membrane. Our findings indicate that the PdPt BNP decoration can effectively enhance the gas separation properties of the membranes.