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(TiO 2 ) 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.