An eco-friendly triboelectric hybrid nanogenerators based on graphene oxide incorporated polycaprolactone fibers and cellulose paper

In this research, an eco-friendly triboelectric nanogenerator (TENG) with high output performance based on poly(caprolactone) (PCL)/graphene oxide (GO) and cellulose paper was developed. PCL/GO fibrous layers consisting of various concentrations of GO nanosheets (0, 0.5, 1, 2, 4 and 8 wt%) were fabricated using a cost-effective and simple electrospinning approach. Moreover, the role of GO concentration as well as the topography, thickness, and size of friction layers on the triboelectric performance was investigated. We realized that PCL/4 wt% GO-cellulose paper produced an open circuit voltage, current density and maximum power density up to 120 V, 2.5 mA/m2 and 72.5 mW/m2, respectively. Results demonstrated that this open circuit voltage was 33% greater than that of flat PCL/4 wt% GO layer, confirming the role of the fibrous structure to promote charge density accumulation. Moreover, a 98% increase in the open circuit voltage was calculated for the TENG containing PCL-4 wt% GO with the dimension of 4 × 4 cm2. The output of triboelectric nanogenerator, driven by human hand tapping, was enough to light up at least 21 blue-light-emitting diodes (LEDs) continuously. This higher performance was attributed to the formation of nanopores and strengthened negative charges on PCL from the fibrous structure and oxygen functional groups of GO, respectively. We believed that the suggested triboelectric nanogenerator with high performance, low-cost and easy fabrication process, as well as biocompatibility, has the potential to be applied for eco-friendly power sources to resolve the electronic waste issue and for self-powered biomedical devices.