Enhancement of photocatalytic oxidation by water-driven piezoelectricity using MoO3/P(VDF-TrFE) mixed matrix membranes

Abstract

In this study, novel mixed matrix membranes (MMMs) composed of MoO3/Poly (vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) with distinctive piezo-photocatalytic properties were prepared. The membranes were made from dopes containing a high ratio of MoO3 to P(VDF-TrFE) (2:1 wt%/wt%) through a modified solvent evaporation method. The addition of MoO3 particles significantly impacted the crystallization and self-polarization of the P(VDF-TrFE) matrix, leading to a substantial increase in total crystallinity from 46.4% to 88.9% and a transformation from α to β phase. The flow-induced piezoelectric potential created an internal electric field, enhancing the spatial separation of photogenerated carriers through the piezoelectric effect. Controlled water flow further promoted the spatial separation of carriers. The developed MMMs demonstrated a high Rhodamine B degradation rate, reaching 83.1% within 45 minutes and over 99% within 90 minutes under natural light conditions. The MoO3/P(VDF-TrFE) MMMs exhibit promising piezo-photocatalytic attributes and hold potential for diverse applications due to their unique combination of piezoelectric and photocatalytic properties.