Utilizing the Undesirable Oxidation of Lead-Free Hybrid Halide Perovskite Nanosheets for Solar-Driven Photocatalytic C(sp³)-H Activation: Unraveling the Serendipity

Hybrid halide perovskites (HHPs), whose every branch generates intrusiveness, have been utilized in solar cells from a broader perspective. However, the inclusiveness of employing HHP as a photocatalyst is in its initial stage. This study mainly focuses on the unexpected utilization of, so far, undesirable material vacancy-ordered MA(2)SnBr(6) quantum dots synthesized from MASnBr(3) nanosheets. Here, the quantum confinement grounded a large blue shift in ultraviolet (UV) and photoluminescence (PL) spectra with a Stokes shift of 420 meV, where the band gap increase is observed as size decreases in MA(2)SnBr(6). Remarkably, MA(2)SnBr(6) exhibits air and moisture stability, better charge transfer, and high oxidation potential compared to MASnBr(3). The first-principles-based atomistic computations reveal the strain relaxation in the Sn-Br framework that structurally stabilizes the MA(2)SnBr(6) lattice. Furthermore, the direct band gap and strongly localized valence band edge give rise to a new potential photocatalyst MA(2)SnBr(6) for efficient solar-driven C(sp(3))-H activation of cyclohexane and toluene under ambient conditions.