Sustainable Upcycling of Waste Tires via Sunlight-Driven Carbonization for High-Performance Fuel Cells

Upcycling approximately 1.7 billion waste tires generated globally each year into functional carbon materials represents a critical milestone in circular chemistry. However, conventional pyrolysis and carbonization of waste tires remain highly energy-intensive, relying on slow heating rates and inefficient radiative heating in electrical furnaces. Herein, we design a nanoscale interface-maximized framework by integrating two-dimensional MoS₂ nanosheets as photothermal nanomaterial directly into actual waste tire precursors. This maximized contact interface enables the photothermal heat generated from the MoS₂ nanosheets to be directly and efficiently transferred to the precursor via conduction. Consequently, the MoS₂-Tire composite reaches 1100 ℃ within 2 s under concentrated natural sunlight, leading to successful conversion into a highly porous carbon supports in less than 1 min. The resulting proton exchange membrane fuel cell (PEMFC) fabricated with this carbon support exhibits a maximum power density of 1048 mW cm^-2, surpassing the commercial Pt/C device (1024 mW cm^-2) while maintaining comparable electrochemical durability. This work demonstrates an electricity-free and sustainable carbonization route, opening new horizons for circular materials chemistry and green energy applications.