This study introduces an efficient method for the depolymerization of poly(ethylene terephthalate) (PET) waste into monomers, specifically dimethyl terephthalate (DMT) and bis-2-hydroxyethyl terephthalate (BHET), using an oxygen-vacancy (V0)-rich catalyst under air conditions. The catalyst, Fe/ZnO nanosheets (NSs), achieves space-time yields (STY) of 505.2 gDMT·gcat−1·h−1 and 957.1 gBHET·gcat−1·h−1, representing 51-fold and 28-fold improvements over reactions conducted under nitrogen (N2). In situ spectroscopy and density functional theory (DFT) calculations reveal that the V0-Zn2+-O-Fe3+ sites play a crucial role in the activation of CH3OH and O2, leading to the formation of CH3OH· and OOH· species, which facilitate the cleavage of C–O bonds and the production of monomers. The catalyst also demonstrates superior tolerance and high catalytic activity in depolymerizing various real PET wastes, including textile scraps, mixed plastics, and degraded materials. A life cycle assessment (LCA) shows that this approach reduces energy consumption by 56.0% and greenhouse gas emissions by 44.5% compared to conventional methods, making it a sustainable solution for PET waste management.This study introduces an efficient method for the depolymerization of poly(ethylene terephthalate) (PET) waste into monomers, specifically dimethyl terephthalate (DMT) and bis-2-hydroxyethyl terephthalate (BHET), using an oxygen-vacancy (V0)-rich catalyst under air conditions. The catalyst, Fe/ZnO nanosheets (NSs), achieves space-time yields (STY) of 505.2 gDMT·gcat−1·h−1 and 957.1 gBHET·gcat−1·h−1, representing 51-fold and 28-fold improvements over reactions conducted under nitrogen (N2). In situ spectroscopy and density functional theory (DFT) calculations reveal that the V0-Zn2+-O-Fe3+ sites play a crucial role in the activation of CH3OH and O2, leading to the formation of CH3OH· and OOH· species, which facilitate the cleavage of C–O bonds and the production of monomers. The catalyst also demonstrates superior tolerance and high catalytic activity in depolymerizing various real PET wastes, including textile scraps, mixed plastics, and degraded materials. A life cycle assessment (LCA) shows that this approach reduces energy consumption by 56.0% and greenhouse gas emissions by 44.5% compared to conventional methods, making it a sustainable solution for PET waste management.