Piezoelectric Photocatalytic BaBi ₄ Ti ₄ O ₁₅ @COFs /PVDF‐TrFE Membrane With Enhanced Built‐In Electric Field for Hydrogen Production

ABSTRACT Piezoelectric photocatalytic water splitting hydrogen production technology has become a very promising solution to address the growth of global energy demand and the low‐carbon transformation. To overcome the challenges of powder catalyst recovery and secondary pollution, we designed a piezoelectric photocatalytic mixed matrix membrane (BBTNC‐MMM) using BaBi ₄ Ti ₄ O ₁₅ @COFs (BBTNC) S‐scheme heterojunction as the functional filler within the PVDF‐TrFE (PT) matrix membrane. The experimental results showed that the piezoelectric response output voltage and hydrogen production of BBTNC‐MMM were 3.8 V and 2072.3 µmol h ⁻¹ m ⁻² respectively, which were more than 3 times and 36 times higher than those of the pure PT membrane. COMSOL simulation showed that the BBTNC not only effectively enhanced the internal electric field, promoting the separation of photogenerated carriers, but also had abundant active sites on its surface. Those promoted the improvement of catalytic efficiency. Meanwhile, the porous membrane structure ensured that sufficient catalytic active sites were exposed to the aqueous environment and provided a path for the transport of reactants/products. This research successfully developed a piezoelectric photocatalytic membrane, providing a new direction for sustainable hydrogen production and piezoelectric response sensing applications.