Enhanced Hydrogen Evolution in Porous and Hybrid g-C₃N₄/Pt-PVDF Electrospun Membranes via Piezoelectricity from Water Flow Energy

Inspired from seaweed swayed by waves, the enhanced hydrogen evolution is realized in porous and hybrid g-C₃N₄/Pt-PVDF electrospun membranes via piezoelectricity from water flow energy. The membranes are fabricated by dispersing g-C₃N₄/Pt into the mixed solution of PVDF and PEO, followed by electrospinning and selective removal of PEO. By changing the PEO amount, the pore size in nanofibers is adjusted. Due to the hydrogen bonding between g-C₃N₄/Pt and PVDF, the β phase of PVDF is increased, beneficial for the piezoelectricity performance. When the electrospun membranes are exposed to water flow, an additional potential field is triggered due to the deformation of PVDF. It not only eases the photogeneration of charge carriers from g-C₃N₄/Pt but also hinders their recombination. The prolonged lifetime significantly improves the photocatalytic water splitting of g-C₃N₄/Pt under visible light. The hydrogen evolution in the electrospun membranes (PVDF to PEO = 4:1) is profoundly improved to 9 278 µmol h⁻¹ g⁻¹, almost doubled to the pure g-C₃N₄/Pt nanosheets (5 220 µmol h⁻¹ g⁻¹). Therefore, the seaweed-inspired electrospun membrane is a promising strategy for the efficiently photocatalytic water splitting via g-C₃N₄ in an aqueous environment, such as a natural sea and lake, by the piezoelectricity gained from the water flow energy.