Visible light driven reform of wasted plastics to generate green hydrogen over mesoporous ZnIn2S4

Abstract

As the global consumption of plastics keeps increasing, the accumulated plastics in the natural environment have threatened the survival of human beings. Photoreforming, as a simple and low-energy way, could transform wasted plastic into fuel and small organic chemicals at ambient temperature. However, the previously reported photocatalysts have some drawbacks, such as low efficiency, containing precious or toxic metal. Herein, a noble-free, non-toxic, and easy prepared mesoporous ZnIn₂S₄ photocatalyst has been applied in photoreforming of polylactic acid (PLA), polyethylene terephthalate (PET) and polyurethane (PU), generating small organic chemicals and H₂ fuel under simulated sunlight. Plastic was degraded into small organic molecules after the pretreatment, which futher acted as the substrate for photoreforming. Mesoporous ZnIn₂S₄ exhibits high H₂ production efficiency, strong redox ability, and long-term photostability. Furthermore, mesoporous ZnIn₂S₄ could overcome the hindrances of dyes and additives of realistic wasted plastic bags and bottles with high decomposition efficiency, providing an efficient and sustainable strategy for the upcycling of wasted plastics.