Waste-based triboelectric nanogenerators for sustainable energy harvesting: a comprehensive review of materials, mechanisms, and energy applications.

The rapid accumulation of waste materials and the rising demand for clean energy have encouraged the development of sustainable technologies capable of converting waste into functional power-generating devices. Waste-based triboelectric nanogenerators (TENGs) represent a sustainable and emerging class of energy-harvesting devices that convert mechanical energy into electricity while utilizing abundant waste-derived materials. This review summarizes recent advances in the use of agricultural residues, fruit and vegetable peels, textile waste, paper waste, plastics, and industrial by-products as triboelectric materials. This discussion emphasizes the prospective benefits of materials obtained from waste, such as economical feedstocks, extensive accessibility, varied surface chemistry, and possibilities for waste valorization. The fundamental operating mechanism of TENGs based on contact electrification and electrostatic induction is briefly outlined, along with key material engineering strategies, such as surface modification, nanostructuring, and composite formation to enhance performance. The review also presents recent developments and applications of waste-based TENGs in wearable electronics, self-powered sensors, environmental monitoring, healthcare, and IoT systems that offer a viable pathway for combining waste valorization with renewable energy harvesting, supporting the development of sustainable and eco-friendly next-generation energy technologies.