Transition Metal Dichalcogenides as Triboelectric Performance Enhancers: Charge Dynamics and Multifunctional Integration in Self‑Powered Systems

The rapid proliferation of the Internet of Things (IoT) and wearable electronics necessitates sustainable and autonomous energy solutions beyond conventional batteries. Triboelectric nanogenerators (TENGs) have emerged as a promising technology for harvesting ambient mechanical energy, yet their practical deployment is often limited by insufficient power density, environmental instability, and material-driven performance constraints. This review provides a critical and timely analysis of the transformative role of two-dimensional (2D) transition metal dichalcogenides (TMDs) in overcoming these barriers and advancing TENG technology toward self-powered intelligent systems. Unlike prior reviews that broadly survey (2D) materials, this work systematically examines the unique physicochemical properties of TMDs such as tunable bandgaps, exceptional electron affinity, superior charge trapping, mechanical flexibility, and environmental resilience that collectively enhance triboelectric output, durability, and functional versatility. We elucidate fundamental mechanisms underpinning performance enhancement, discuss scalable synthesis strategies, and highlight emerging applications in energy harvesting, self-powered sensing, human-machine interfaces (HMI), and biomedical devices. By consolidating recent progress and recognizing current obstacles, this review seeks to offer a comprehensive perspective on the capabilities of TMDs in the TENG domain and to stimulate future investigations toward creating advanced high-efficiency triboelectric electronics.