Engineering BiOBr I solid solutions with enhanced singlet oxygen production for photocatalytic benzylic C–H bond activation mediated by N-hydroxyl compounds

Abstract The aerobic, selective oxidation of hydrocarbons via C−H bond activation is still a challenge. This work shows the achievement of the room temperature visible light driven photocatalytic activation of benzylic C−H bonds with N-hydroxysuccinimide over BiOBrxI1-x (0 ≤ x ≤ 1) solid solutions, whose valance bands were engineered through varying the ratio of bromide to iodide. The optimal BiOBr0.85I0.15 catalyst exhibited over 98% conversion ratio of ethylbenzene, which was about 3.9 and 8.9 times that of pure BiOBr and BiOI, respectively. The excellent photocatalytic activity of BiOBr0.85I0.15 solid solution can be ascribed to the orbital hybridization of the valence band containing both Br 4p and I 5p orbitals, which could promote photo-induced charge carrier separation and improve the generation of singlet oxygen. This work shed some light on the rational design of photocatalysts for targeted organic transformation.