Ultrafast and highly‐selective upcycling of plastic polylactic acid waste driven by ZnInFe‐mixed metal oxide

Chemical upcycling of waste plastics represents an appealing way to achieve a circular economy and mitigate environmental problems but remains a huge challenge. Herein, we report a heterojunction photocatalyst (ZnInFe-mixed metal oxide, denoted as ZnInFe-MMO) for the rapid valorization of polylactic acid (PLA) via a developed alkali-assisted photocatalysis system. The ZnInFe-MMO featured with a double Z-Scheme structure is favorable for light harvesting and electron-hole separation. Moreover, the operando characterizations and theoretical simulations confirm that the ZnInFe-MMO affords a remarkably decreased barrier for the rate-determining step (formation of *LA intermediate) while inhibiting the CC breakage in the side reaction. As a result, the ZnInFe-MMO attains a ~100% conversion and ~99% selectivity toward sodium lactate (NaLA), which is preponderant to the state-of-the-art photocatalysts. In addition, such an effective route is also demonstrated in various real-world PLA waste.