Synergistic β-Phase and Dielectric Amplification in Recycled ZnO micro- sphere/GO/PVDF Hierarchical Porous Composites

The escalating demand for high-performance, sustainable materials in next-generation electronics has driven innovation in piezoelectric composites. This study presents a sustainable approach to fabricating advanced PVDF-based hybrid membranes by incorporating recycled ZnO microspheres and graphene oxide (GO) through a facile solution-casting technique. Building on established strategies that utilize ZnO and GO to enhance PVDF’s β-phase content, a critical factor for piezoelectric performance. We synergistically combine these fillers to amplify functional properties. The characterization using X-ray diffraction (XRD, Infra-red (FT-IR), and scanning electron microscopy (FE-SEM) confirmed that GO’s structural defects and reduced lattice dimensionality act as nucleation sites, fostering a 72% β-phase ratio in PVDF, a 30% increase over pristine PVDF. Density functional theory (DFT) calculations elucidate how interfacial interactions between ZnO, GO, and PVDF chains elevate the total dipole moment (by ~18%) and electrostatic potential, while increasing the bandgap energy (from 2.1 eV to 3.4 eV), directly correlating to enhanced piezoelectric response. Electrical conductivity studies reveal a 5-order-of-magnitude improvement (up to 10⁻³ S/cm) compared to pure PVDF, attributed to GO’s conductive pathways and ZnO’s charge polarization. By integrating recycled ZnO with GO a novel dual-filler strategy. This work advances eco-friendly and commercial piezoelectric materials, demonstrating exceptional potential for wearable sensors, energy harvesters, and flexible electronics. The findings align with global sustainability goals while offering a scalable fabrication route, bridging the gap between theoretical innovation and practical application in functional composites.