A simple and low-cost triboelectric nanogenerator based on two dimensional ZnO nanosheets and its application in portable electronics

The exploration of new triboelectric materials is considered a significant research area to reduce the cost and complexity of the triboelectric nanogenerator (TENG) device and improve its energy conversion efficiency. In this report, a new triboelectric material pair has been demonstrated to prepare an inexpensive and high-performance TENG. A low-cost hot plate-assisted hydrothermal process is used to prepare the ZnO nanosheets on an aluminum substrate. TENG is made using ZnO nanosheet film, PET/ITO, and operates in vertical contact separation mode. The proposed TENG generates electricity through contact electrification and electrostatic induction. The fabricated TENG is tested for the switching polarity test and confirmed the output voltage generated by TENG alone. The TENG can deliver an open-circuit voltage and short-circuit current of ~ 4.9 V and 10 µA, respectively, for repeated hand tapping. Further, the performance of the proposed TENG is tested under resistive loads, and the maximum power density of 1 µW/cm2 observed at a load resistance of 5 MΩ. Similarly, TENG is also tested under capacitive loads and found the maximum energy stored value of 16.9 μJ at the load capacitance of 47 μF. In addition, the effect of different frequencies of the applied force and device size on the TENG response is studied. The TENG can light up 3 LEDs instantaneously and power the digital watch and 24 LEDs using an energy storage element. The present TENG shows a low-cost and straightforward process and can harvest energy from low-frequency bio-mechanical vibrations. The proposed TENG has potential applications in self-powered electronic devices and systems.