2D materials integrated with polymers for sustainable energy harvesting through triboelectric nanogenerators

In recent years, there has been a surge in the usage of fossil fuels to generate energy from it, like oil, petroleum, coal and natural gas across industrial, vehicles and daily life sectors. Triboelectric nanogenerators (TENGs), among others, have attracted a lot of interest due to their stability and portability. They have very high energy conversion efficiency. The fusion of triboelectric nanogenerators (TENGs) with 2D nanomaterials has given rise to TENGs based on 2D nanomaterials (2D-TENGs). The exceptional physical, optical, chemical, and electronic properties inherent in 2D nanomaterials confer improved output performance upon 2D-TENGs. This review comprehensively shows the current state of work in 2D-TENGs, covering their basic classifications, output performances (voltage, current and power), mechanisms including their enhancements, exceptional advantages, and applications regarding harvesting energy through human motion, wind, rainwater, ocean, vibrations and sonic. It also addresses several challenges that may hinder the widespread application of 2D-TENGs.