Piezoelectric Energy Harvesting from Thermal Vibrations Using Doped Graphene-MXene Heterostructure

Piezoelectric nanogenerators (PENG) can face challenges when integrated into high-temperature applications because of their temperature sensitivity. Heterostructures of specific 2D nanomaterials can potentially enhance PENG performance for practical applications at high temperatures. This study incorporated nitrogen-doped graphene (NGr) and Ti3C2Tx MXene heterostructure nanofillers into the polyvinylidene difluoride (PVDF) matrix for energy harvesting in a high-temperature vibration environment. The solution processable nanogenerator device is achieved by optimizing the appropriate ratio of NGr to Ti3C2Tx. At room temperature, the nanogenerator showed an optimum output voltage of ~9.0 V and ~1.5 μA of current. Thereby, it raised to 24.0 V and 1.75 μA when the temperature increased to 90 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup>C, obtaining a power density of 3.85 μW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. This outstanding performance is attributed to the designed NGr-Ti3C2Tx quasi-3D heterostructure, where its rich interfacial features, excellent electrical conductivity, and localized elastic complexes synergistically promote the piezoelectric output of the energy harvester. Placing the device on the road could be used to collect the mechanical energy generated by the vibration of the car’s movement and convert it into electrical energy, which opens up new development possibilities for addressing emerging energy issues.