Tunable Self-Poled2D h‑BN/PVDF Nanofibersfor Enhanced Electromechanical and Electrochemical Applications

Nowadays, flexible piezoelectric energy harvesters (PEHs) have drawn much attention as a sustainable solution for generating electrical energy from biomechanical motion to power wearable and portable electronic devices. In this work, we present a substantial enhancement in the power output derived from a human-body-motion-based PEH by utilizing a self-polarized nanocomposite composed of two-dimensional (2D) hexagonal boron nitride (h-BN) nanosheets and poly(vinylidene fluoride) (PVDF). Extensive analysis of the structural, microstructural, and piezoelectric properties revealed that the 1.5 wt % h-BN-incorporated PVDF nanocomposite (PEH1.5) is the most suitable material for energy harvesters. 2D material-based PEH1.5 demonstrated excellent power generation, producing a maximum voltage output of 35 V and a 4.8 μA current under a periodic force of 15 N, with a power density of 17.5 μW/cm². This improved performance is due to the high surface area of the 2D h-BN nanosheets, which facilitates the development of the electroactive phase in the PVDF matrix, significantly boosting its piezoelectric characteristics. The alternating current electrical energy generated by the PEH1.5 is effectively used to illuminate 10 commercial LEDs and capacitor charging through a bridge rectifier. Additionally, the device exhibited pressure sensitivities of 1.248 V/kPa in low-pressure and 0.881 V/kPa in medium-pressure ranges, facilitating the reliable detection of biomechanical signals associated with a range of human activities. Beyond energy harvesting, the nanocomposite film demonstrated a notable piezo-catalytic response, achieving 75% degradation of crystal violet dye through reactive oxygen species production under mechanical stress. This dual functionality highlights the potential of the nanocomposite for both energy harvesting and environmentally sustainable applications, such as wastewater purification. Overall, this work presents an approach for energy harvesting using 2D material-based h-BN/PVDF nanocomposites, offering a promising solution for self-powered flexible electronics that not only harness biomechanical energy but also contribute to environmental sustainability.