Graphene-Coated PVDF/PAni Fiber Mats and Their Applications in Sensing and Nanogeneration.

Forcespinning is a powerful technique to produce fiber systems with suitable properties for a vast array of applications. This study investigates the sensing and energy generation performance of PVDF/PAni fiber mat systems made by the forcespinning method with and without graphene coating. The developed fiber mats were coated with graphene nanoflakes by drop-casting. The graphene-coated nanocomposites show an average output voltage of 75 mV (peak-to-peak), which is 300% higher compared to bare fiber mats, and an output current of 24 mA (peak-to-peak) by gentle finger pressing. Moreover, graphene-coated PVDF/PAni showed a volume conductivity of 1.2 × 10 -7 S/cm and was investigated as a promising system for temperature (5 times better sensitivity than normal fiber mat), vibration (2 times better voltage generation), and airflow sensing. The graphene-coated composite has been further investigated as a water tide energy harvesting piezoelectric nanogenerator, with the system generating ∼40 mV for a synthetic ocean wave with a flow rate of 30 mL/min. In the future, graphene-coated nanofiber mats can be a solution for low-powered sensors and to harvest blue energy and vibration energy.