Enhanced induced charge in ramie-inspired triboelectric layer towards trace oil detection

The oil leakage on the ocean leads to the inevitable and critical environment crisis, indicating the self-powered alerts with the high sensitivity are rather crucial for the early detection, as well as for extended periods with low consumption. Inspired by the ramie leaf, we fabricated an electrospinning fiber polytetrafluoroethylene (EF-PTFE) film, and prepared a rolling pendulum-based triboelectric nanogenerator (RP-TENG) detector with the EF-PTFE surface, whose fiber morphology can realize the distinguishable interaction between oil and water, leading to different charge transfer. Besides, the compressible structure of EF-PTFE film can enhance the effect on the induced charge, thereby improving the TENG output. The open-circuit voltage (V OC ) can increase from approximately 11 V to 15 V. Moreover, the absorption to the trace oil contributes to the high sensitivity, even the diesel concentration below 0.01 mL/m² on the water surface can be well detected. The RP-TENG can also identify petroleum and its derivatives. Furthermore, the TENG sensors with distinguishable absorption also can be extended to the detection of the trace chemicals, promoting the significant applications in multi-functional sensing.