Hot Electron Photocatalysis Using Nontoxic Self‐Doped Quantum Dots

Colloidal semiconductor quantum dots (QDs) have emerged as versatile photocatalysts for organic transformations. However, a significant drawback is their reliance on toxic metals like lead and cadmium, which limits their widespread application in solar‐to‐chemical conversion. Furthermore, current systems primarily utilize band‐edge carriers for simpler photoredox reactions, while the potential for harvesting hot carriers in chemical transformations remains largely unexplored. To address these challenges, we developed nontoxic, cost‐effective, and recyclable ternary CuInS 2 and quaternary Cu─In─Zn─S QDs as potent photocatalysts. Our findings demonstrate that hot electrons can be effectively generated through an ultrafast Auger process, enabling the photoreduction of aryl halides (with reduction potentials up to −2.90 V versus saturated calomel electrode (SCE)) and various cross‐coupling (C─C, C─P, C─B, and C─S) transformations. Notably, quaternary Cu─In─Zn─S QDs exhibit significantly higher reactivity compared to CuInS 2 QDs, which is attributed to enhanced Auger‐mediated hot electron generation. This work underscores the potential of directly utilizing Auger‐generated hot electrons for extreme‐potential organic transformations under mild conditions using nontoxic QDs.