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

Abstract

Abstract 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 CC 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.