Multifunctional Integration of 2D Materials in Triboelectric Nanogenerators: Fundamentals, Material Classification, and Emerging Applications

Triboelectric nanogenerators (TENGs) have emanated as promising platforms for mechanical energy harvesting and self‐powered sensing. However, the performance limitations of conventional polymer and metal‐based triboelectric materials necessitate advanced functional alternatives. Two‐dimensional (2D) materials offer tunable electronic structures, exceptional surface‐to‐volume ratios, and rich surface chemistry that collectively enhance triboelectric charge density, charge trapping, and electromechanical conversion efficiency. This primer critically and systematically examines the multifunctional integration of these materials as active triboelectric layers, high‐performance electrodes, and bifunctional components across diverse TENG configurations. Beyond mechanical energy harvesting, emerging applications encompassing self‐powered chemical, pressure, and physiological sensors, as well as TENG‐driven electrochemical water splitting for green hydrogen production, are highlighted. Persistent challenges related to large‐scale synthesis, long‐term stability, charge recombination, and standardized evaluation protocols are critically assessed. Future directions emphasize van der Waals heterostructures, fully integrated 2D‐material device architectures, and artificial intelligence (AI)‐assisted adaptive energy systems, positioning 2D‐TENG technology as a cornerstone of next‐generation self‐powered intelligent platforms.