Nanointerface Insights in PVDF Films with Low Loadingof Nitrogen-Doped Carbon Dots for High Energy Density Storage andHarvesting

This work demonstrates the enhancement of the electroactive phase of the nanocomposite, resulting in a high energy density storage and piezoelectricity. Low loading (≤1 wt %) of synthesized nitrogen-doped carbon dots (N-CDs) reinforced in poly(vinylidene fluoride) (PVDF) accelerated the formation of electroactive phases with conformational changes in the polymer chain. The addition of 1 wt % N-CDs to the PVDF polymer matrix increased the dielectric constant by 2.18 times, and the maximum polarization reached a multiplication of 2.32 compared to pure PVDF films. Moreover, a 1.62 times enhancement in the piezoelectric coefficient <i>d</i>₃₃ resulted in a voltage sensitivity of 22.28 mV/N for as low as 1% filler reinforcement. The simulation results further confirmed the increase in dielectric constant and piezoelectric coefficient. The N-CD-integrated PVDF films are promising candidates for energy storage and harvesting applications.