Recyclable CdS/PVDF Composite Films for Enhanced Photocatalytic Hydrogen Production: Water Flow Drives Piezo‐Photocatalysis

ABSTRACT The induced polarized electric field in the piezoelectric film promotes efficient carrier separation, which is a promising strategy for semiconductor photocatalysts to improve photocatalytic hydrogen evolution activity. In this work, PVDF@CdS@PVDF sandwich‐like flexible composite film has been fabricated via magnetron sputtering. The dynamic piezoelectric field produced by low energy density water flow on bi‐layer PVDF is advantageous for bulk charge transfer and separation. The hydrogen evolution rate of the optimal PVDF@CdS@PVDF composite film reaches 1313.3 µmol g −1 h −1 owing to the dual‐polarized electric field, which is 14 times higher than the pure CdS photocatalyst. In addition, the theoretical simulation confirms that the piezoelectric effect of the dual PVDF film facilitates the suppression of photogenerated carrier recombination. From a broader perspective, this work sheds light on flexible and recyclable composite photocatalyst films for efficient clean energy.