Efficient\nPhotoredox Co-Upcycling of CO<sub>2</sub> and Plastic Waste by Band-Gap-Engineered\nZn<sub><i>x</i></sub>Cd<sub>1–<i>x</i></sub>S Catalyst

Solar-driven CO<sub>2</sub> reduction combined with plastic\nwaste\nvalorization presents a versatile approach to simultaneously reset\nmisaligned hydrocarbon resources and achieve a carbon-neutral cycle.\nHerein, we demonstrate a co-upcycling heterogeneous photoredox catalysis\nfor efficient CO<sub>2</sub> reduction to tunable syngas, integrated\nwith polyethylene terephthalate (PET) plastic conversion for accessing\nacetate, over the spherical band-gap-engineered Zn<sub><i>x</i></sub>Cd<sub>1–<i>x</i></sub>S catalyst. The key\nto steering the syngas H<sub>2</sub>/CO rate is to modulate the conduction\nband bottom potentials of the Zn<sub><i>x</i></sub>Cd<sub>1–<i>x</i></sub>S photocatalysts by altering the\nZn/Cd ratio, which results in syngas H<sub>2</sub>/CO production over\na wide range. Moreover, controlled variations in the molar ratio of\nZn/Cd regulate the electron–hole separation capability, thereby\nendowing Zn<sub>0.8</sub>Cd<sub>0.2</sub>S with the optimum syngas\nand acetate production rates. The underlying mechanistic origin of\nsuch a redox reaction involving CO<sub>2</sub>-assisted PET plastic\nconversion has been systematically investigated. This win-win cooperative\nphotoredox catalysis offers a tantalizing possibility for co-upcycling\nof CO<sub>2</sub> and PET into value-added feedstocks.