Piezoelectric-Fenton degradation and mechanism study of Fe2O3/PVDF-HFP porous film drove by flowing water.

Piezocatalysis driven by a gentle force possesses broad application prospects for degrading organic pollutants, sterilisation, wound healing and tissue recovery. The flexible and industrially scalable poly(vinylidene fluoride) (PVDF) film is commonly used in piezocatalysis. However, under gentle force action, PVDF composite-based piezocatalysis is poor. Herein, a flexible porous film based on poly(vinylidene fluoride)-hexafluoro propylene (PVDF-HFP) is enhanced with Fenton fillers (α-Fe2O3 nanoparticles). α-Fe2O3 nanoparticles improve the piezoelectric catalysis performance of PVDF-HFP by the ß-phase enhancement and provide Fe3+ to react with H2O2 generated by the piezoelectric film itself, leading to an additional Fenton reaction. Meanwhile, the Fe3+/Fe2+ cycle in the Fenton process accelerates under the piezoelectric field, promoting the Fenton reaction for 6.9% degradation improvement. The study on Fe2O3/PVDF-HFP porous film with the piezo-Fenton reaction under flowing water may help promote new piezocatalysis designs with high efficiency for self-powered environmental purification.

Synergistically Active Piezoelectrical H2 O2 Production Composite Film Achieved from a Catalytically Inert PVDF-HFP Matrix and SiO2 Fillers.

Local and decentralized H2 O2 production via a piezoelectrical process promises smart biological utilization as well as environmental benefits. However, stable, bio/environmentally safe, and easily applied H2 O2 generation materials are still lacking. Here, we report a novel flexible H2 O2 generation polymeric film composed of catalytically inert PVDF-HFP (Poly(vinylidene fluoride-co-hexafluoropropylene)) matrix and SiO2 nanoparticle fillers. The film is bio-/environmentally benign at resting states, but effectively produces H2 O2 upon ultrasonic motivation at a production rate of 492 µmol g SiO 2 - 1 in one hour. Experimental and simulation methods in combination indicate that the effective H2 O2 generation capabilities stem from the synergistic existence of piezoelectrical fields and the air-liquid-solid three-phase regions around the porous film. The chemical conversions are motivated by the adsorbed charges. The silicon hydroxyl groups properly stabilize the *OOH intermediate and facilitate the chemical conversions of 2e- ORR of ambient O2 . We expect the report to inspire H2 O2 piezoelectrical generation materials and promote the novel production strategies of H2 O2 as well as piezoelectrical functional materials.