Stable lead-halide perovskite quantum dots as efficient visible light photocatalysts for organic transformations

Abstract

Lead halide perovskite (LHP) based colloidal quantum dots (CQDs) have tremendous potential for photocatalysis due to their exceptional optical properties. However, their applicability in catalysis is restricted due to poor chemical stability and low recyclability. We report halide-passivated, monodisperse CsPbBr3CQDsas a stable and efficient visible-light photocatalyst for organic transformations. We demonstrate oxidative aromatization of a wide range of heterocyclic substrates including examples which are poor hydrogen transfer (HAT) reagents. Two to five-fold higher rate kinetics were observed for reactions catalyzed by CsPbBr3CQDsin comparison with bulk-type CsPbBr3(PNCs) or conventionally synthesized CsPbBr3CQDsand other metal organic dyes (rhodamine 6G and [Ru(bpy)3]2+). Furthermore, theseCQDsexhibit improved air-tolerance and photostability and in turn show a higher turnover number (TON) of 200, compared to conventionally preparedCQDs(TON = 166) and state-of-the-art bulk-type perovskite-based catalyst (TON = 177). Our study paves the way for the practical applicability of energy-level tunable, size-controlled LHPCQDsas efficient photocatalysts in organic synthesis.