Sustainable paper-based triboelectric nanogenerator with improved output performance through a general strategy of interface fusion

The paper-based triboelectric nanogenerators (PB-TENGs) satisfied the requirement of sustainability and aroused great research interests, however how to improve their outputs still remains as a huge challenge. Most of the reported strategies to enhance the performance of PB-TENG focused on the chemical modification of the friction layers (FL), which may be restricted by the high-cost and cumbersome protocols being required. In this work, a general strategy of interface engineering to boost the outputs of the PB-TENG was proposed and validated by employing graphene composite paper (GC-paper) as electrodes. At the beginning, the hydroxyethyl cellulose (HEC) and Ecoflex were cured as separated films and used as friction layers, which were adhered with copper or GC-paper electrodes. The PB-TENG device can be obtained and possess acceptable performance. Subsequently, we were surprised to find that the outputs of the PB-TENG largely increased by coating the FLs on the GC-paper rather than adhering. The maximum open-circuit voltage jumped from 300 V to 734 V, and the maximum short-circuit current boosted from 3.4 µA to 8.7 µA. This phenomenon may be ascribed to an interface effect between the FLs and electrodes, which enhanced the electrostatic induction. The strategy of this interface engineering was also proved to be general for other PB-TENG devices with various friction materials. Therefore, it may pave a way for the development of sustainable TENG devices with high performance.