Olefin separation via charge transfer and dipole formation at the silver nanoparticle–tetracyanoquinoid interface

In this study, we report the significantly increased carrier activity of AgNPs in silver–olefin complexation, induced by the addition of tetracyanoquinoidal molecules (TCQs) such as TCNQ and F4-TCNQ. The interactions between AgNPs and TCQs were investigated by UV-Vis spectroscopy. The Kelvin probe and XPS data revealed vacuum level shifts and dipole formation at the AgNPs–TCQs interface, resulting in the increased work function of the AgNPs from 4.89 up to 5.25 eV. As a result, membranes containing AgNPs–TCQs demonstrated a mixed gas selectivity of ca. 100 for a 50/50 (vol%) propylene–propane mixture and showed stable performances.