Unravelling the impact of carbon allotropes in flexible polydimethylsiloxane film towards self-powered triboelectric humidity sensor

The influence of surface charge on tribo-layer is a crucial parameter in improving the performance of triboelectric nanogenerators (TENG). Nevertheless, most researchers focus on the structure and design of TENG rather than increasing the surface charge density, which is the main parameter for energy harnessing in nanogenerators. Herein, we tweaked the surface charge density of polydimethylsiloxane (PDMS) via incorporating different types of carbon allotropes to shift the charge density (positive to negative and vice versa) for high output TENG. The PDMS/GO TENG device generated a voltage of 234 V; higher compared to that of bare PDMS and other nanocomposite films, which is attributed to the high surface charge of PDMS/GO confirmed via Kelvin probe force microscopic (KPFM) analysis. As a proof concept, we have demonstrated the use of PDMS/GO-based TENG device for self-powered humidity sensor.