C(sp³)–H Bond Activation by Perovskite Solar Photocatalyst Cell

Inspired by efficient perovskite solar cells, we developed a three component hybrid perovskite-based solar photocatalyst cell, NiOx/FAPbBr(3)/TiO2, for C(sp(3))-H bond activation with high selectivity (similar to 90%) and high conversion rates (3800 mu mol g(-1) h(-1)) under ambient conditions. Time-resolved spectroscopy on our photocatalytic cell reveals efficient exciton dissociation and charge separation, where TiO2 and NiOx serve as the electron- and hole-transporting layers, respectively. The photogenerated charge carriers injected into TiO2 and NiOx drive the challenging C-H activation reaction via the synergetic effects of their band alignment relative to FAPbBr(3). The reaction pathway is investigated by controlling the free-radical formation, and we find that C-H activation is mainly triggered by hole oxidation. Besides aromatic alkanes, also the C(sp(3))-H bond in cycloalkanes can be oxidized selectively. This work demonstrates a generic strategy for engineering high-performance photocatalysts based on the perovskite solar cell concept.