PVDF/Ag2CO3 nanocomposites for efficient dye degradation and flexible piezoelectric mechanical energy harvester

Currently, the demand for flexible, light-weight and portable electronic devices for high energy storage is increasing, which are important for sensors and actuators. Accordingly, flexible piezoelectric polymer nanocomposites have attracted significant attention because of their outstanding piezo-, pyro-, and ferro-electric properties. Herein, we report the synthesis of a PVDF/Ag2CO3 nanocomposite having an electroactive gamma-phase with high dielectric constant and mechanical energy harvesting applications. The formation of the gamma-phase was confirmed by FTIR spectroscopy and the probable mechanism behind the alpha- to gamma-phase formation was further illustrated via favourable C-C bond rotation to attain a stable conformation, which was driven by Ag charge nucleation. Further, we investigated the inter-fragment, non-covalent, intermolecular interactions between PVDF and the silver carbonate filler (Ag2CO3) via density functional theory (DFT) based on the linear combination of atomic orbitals (LCAO) approach. The fabricated PVDF/Ag2CO3 nanocomposite-based flexible piezoelectric nanogenerator (FPNG) showed an excellent electrical output response, mechano-sensitivity (S), acoustic signal and human gesture sensing performance. Additionally, the piezo-catalytic response of the nanocomposite film was demonstrated via the efficient degradation of methyl orange (MO) dye. This phenomenon was further explained by the generation of in situ reactive oxygen species (ROS) in the nanocomposite matrix. The mechano-catalytic dye degradation (D) was estimated to be similar to 80%. Thus, it is expected that piezo-catalytic-driven dye degradation can provide highly efficient and reusable technology for organic dye removal and wastewater purification.