Clitoria ternatea flower extract: Biopolymer composite-based triboelectric nanogenerator as a self-powered smart counter

The development of biopolymers-based high-performance triboelectric nanogenerators (TENGs) for powering innovative electronics is crucial for green energy technologies. Herein, a novel TENG composed of polyvinyl alcohol (PVA) functionalized with electron-donating groups from Clitoria ternatea (CT) flower extract is proposed. The compatibility of composite film in energy harvesting devices is tested through various characterizations, including structural, surface, electrical, and bioassay. Interestingly, the enhanced tribopositivity of the composite is attributed to intermolecular hydrogen bonding between taraxerol and PVA, substantiated by Hartree-Fock-DFT calculated vibrational spectrum, frontier molecular orbital energy gap, and electrostatic potential maps. TENG with PVA-CT: Polyurethane generated an open-circuit voltage (V_OC) of 14.8 times and short-circuit current (I_SC) of 32.7 times, more significant than PVA TENG and several bio/non-biodegradable tribonegative polymers. The long-term stability test of PVA-CT TENG is confirmed by an observation of constant V_OC for eight consecutive months. Additionally, humidity studies reveal that output increases with an increase in relative humidity of 30–100%. Further, the PVA-CT TENG is efficient in charging capacitors, powering LEDs, and acts as a self-powered smart counter. Overall, this study contributes new insights into developing eco-friendly synergistic materials for TENG fabrication and extending its applications in the Internet of Things, facilitating to build of futuristic smart cities.