Flow-driven piezo-photocatalytic synergy in Bi24O31Br10/β-PVDF membranes: Interfacial electron transfer-mediated enhancement of tetracycline degradation

Photocatalytic membrane technology has gained considerable attention due to its mild reaction conditions, simple operation, and lower secondary pollution. However, conventional photocatalytic membranes often exhibit notably lower activity compared to powder catalyst, mainly owing to inefficient interfacial charge transfer and limited accessibility of active sites. Herein, we developed a novel porous Bi₂₄O₃₁Br₁₀/β-PVDF piezoelectric membrane with enhanced fluid-induced piezoelectric potential. Experimental results confirm strong interfacial coupling between Bi₂₄O₃₁Br₁₀ and the β-PVDF matrix synergistically improved the surface hydrophilicity and piezoelectric polarization of Bi₂₄O₃₁Br₁₀/β-PVDF piezoelectric membrane. Therefore, the optimized Bi₂₄O₃₁Br₁₀/β-PVDF piezoelectric membrane achieves exceptional tetracycline (TC) degradation efficiency of 99.73 %, even outperforming both the Bi₂₄O₃₁Br₁₀ powder sample (91.93 %) and non-piezoelectric Bi₂₄O₃₁Br₁₀/α-PVDF membrane (59.19 %) with equivalent catalyst loading. In-situ piezoelectric measurements and electrochemical analyses further revealed that the fluid-induced piezoelectric field on Bi₂₄O₃₁Br₁₀/β-PVDF piezoelectric membrane significantly promoted the separation of photogenerated charge carriers, thereby boosting the membrane’s catalytic efficiency. This study provides a novel approach for enhancing the efficiency of Bi-based photocatalysts and opens up a new path for the development highly efficient and stable photocatalytic membrane system.