Multifunctional 3D-MXene/PDMS nanocomposites for electrical, thermal and triboelectric applications

•Pure 3D-MXene skeleton with long-range ordered microstructures was fabricated.•3D-MXene/PDMS composites exhibit a through-plane TC enhancement of 220% at a low skeleton content.•For the first time, 3D-MXene skeleton was used to improve electrical output performance of triboelectric nanogenerators. Highly conductive and flexible materials have many applications in the electrical and electronic fields, while the realization of high electrical/thermal conductivity by a green, simple and efficient approach is still challenging. Herein a simple method was proposed to construct three-dimensional Ti3C2Tx (3D-MXene) skeleton without using adhesive agents. After incorporated into polydimethylsiloxane (PDMS) matrix, the resultant 3D-MXene/PDMS nanocomposites exhibited excellent electrical conductivity of 5.5 S/cm, which was nearly 14 orders of magnitude higher than that of the neat PDMS. On the other hand, the nanocomposites show a thermal conductivity enhancement of about 220% at a low MXene content of 2.5 vol% in comparison with neat PDMS. Moreover, the output current of 3D-MXene/PDMS based triboelectric nanogenerators (TENGs) was greatly enhanced because of the significantly decreased electrical resistance. This finding can be applied to TENGs with capacitor structures and can also widen the practical applications of MXene in the field of thermal management, sensors and energy harvesters.