Tenon-and-Mortise Structure-Inspired MOF/PVDF Composites with Enhanced Piezocatalytic Performance via Dipole-Engineering Strategy

Abstract

Fabricating poly(vinylidene fluoride) (PVDF) and its composite ferroelectrics are essential for the development of next-generation lightweight, portable, wearable, and implantable intelligent devices. However, integrating and maximizing spontaneous polarization and interfacial electromechanical conversion efficiency remain major challenges in the contemporary PVDF-based composites field. Herein, inspired by the tenon-and-mortise structure associated with ancient Chinese architecture, an amino-anchored metal–organic framework (MOF)/PVDF piezoelectric composite using a dipole-engineering strategy to deliver enhanced piezocatalytic performance is constructed. Homogeneous and long-range ordered hydrogen-bond networks have been formed with the PVDF matrix after introducing periodically arranged amino anchors into the NH2-HU MOF. The NH2-HU10wt%/PVDF composite exhibits a 40% greater β-phase content and a remnant polarization value more than 550% higher than that of the bare PVDF fibers. These amino anchors synergistically enhance both the local electric field and collaborative dipole alignment resulting in a piezocatalytic bactericidal performance of 97.4% when irradiated under clinical ultrasound conditions. Moreover, the enhanced polarizability within the MOF/PVDF composite simultaneously improves its responsiveness to X-rays via its periodic amino anchoring networks, thereby doubling CT imaging efficacy for implants at lower voltages. Integrating piezoelectric MOFs and polymer matrices through molecular design presents a viable approach for optimizing ferroelectric properties and expanding piezoelectric-composite applications.