Enhanced Piezoelectric Photocatalysis Performance of Polymers/P25 Nanofibers on Rhodamine B Remediation via Polar Functional Group Engineering

The recent advancements in harvesting solar and mechanical vibrations are ubiquitous for environmental remediation. Hereon, we report that flexible piezo- and photocatalytic composite nanofiber mats are prepared by electrospinning to enhance photocatalytic efficiency for environmental remediation. P25(TiO2) nanoparticles were composited with polymers containing different functional groups and percentages (PAN, PVDF, and PVDF–TrFE). Our results demonstrated that the catalytic activity of polymers/P25 nanofibers in photodegradation of rhodamine B (RhB) can be greatly enhanced by environmental vibration-induced piezoelectricity of polymer nanofibers. PVDF–TrFE/P25 nanofibers with more functional groups (–F) exhibited a maximum enhanced catalytic activity factor of ∼2.0 (rate of 0.065 min–1) by achieving a higher piezoelectric voltage of 377 mV. The working mechanism for the enhanced photocatalytic activity of polymers/P25 nanofibers can be ascribed to the piezoelectric effect of polymers, which brings a higher separation efficiency of photogenerated electron–hole pairs and a lower recombination efficiency. The enhancement of the piezoelectric effect of polymers can be strengthened by being modified with high-electronegativity functional groups (–F). It was concluded that the greater electronegativity of the functional groups in the polymer fibers brought a stronger built-in electric field and obtained higher photocatalytic activity.