Exploring the bifunctional properties of paper-like carbyne-enriched carbon for maintenance-free self-powered systems

Abstract

Self-powered systems (SPSs) have become promising power sources in this modern era mainly due to their ability to harvest and store energy in a single system. Herein, we report the bifunctional properties of a free-standing paper-like carbyne-enriched carbon (P-CEC) film (derived from dehydrohalogenation of PVDF) that can be used as an energy harvester (triboelectric nanogenerator) and storage unit (supercapacitor) in SPS. The changes in work function and surface potential of the P-CEC film after the dehydrohalogenation process were carefully investigated via Kelvin probe force microscopy (KPFM) and ultraviolet photoelectron spectroscopy (UPS). The fabricated P-CEC TENG generated a peak-to-peak voltage of ∼126 V (with an applied force of 15 N), which is superior compared to the state-of-the-art of polymer-based TENG. Furthermore, the fabricated P-CEC symmetric supercapacitor (SSC) possess an excellent energy density (109 nW h cm⁻²), power density (2200 μW cm⁻²) and a long cycle-life. The integration of P-CEC-based TENG and SSC into an effective SPS unit demonstrated the ability of TENG to charge the SSC up to 750 mV within 380 s. These results show that the development of bifunctional materials such as P-CEC has a great potential for the maintenance-free SPS systems.