Constructing a Cs3Sb2Br9/g-C3N4 Hybrid for Photocatalytic Aromatic C(sp3)?H Bond Activation

Utilizing halide perovskites for photocatalytic aromatic C( sp 3 )  H bond activation remains a great challenge due to the serious recombination of photogenerated charge carriers and slow reaction dynamics of the materials themselves. Herein, a lead-free perovskite-based hybrid of Cs 3 Sb 2 Br 9 /g-C 3 N 4 nanosheet is constructed and applied for photocatalytic aromatic C( sp 3 )  H bond activation, which shows enhanced photocatalytic performance. By introducing ultrathin g-C 3 N 4 nanosheets as the heterogeneous nucleation sites, size-reduced and well-dispersed Cs 3 Sb 2 Br 9 nanocrystals can be obtained. The as-formed close contact and high-quality heterointerface between Cs 3 Sb 2 Br 9 and g-C 3 N 4 provides pathways for fast charge transfer which is beneficial to improve the separation efficiency of photogenerated electron−hole pairs. Under visible light irradiation, the Cs 3 Sb 2 Br 9 /g-C 3 N 4 hybrid photocatalyst can effectively oxidize toluene toward benzaldehyde and benzyl alcohol with a total conversion rate of 8346.8 μmol g −1 h −1 , which is 26.6- and 6.0-fold that of pure g-C 3 N 4 and Cs 3 Sb 2 Br 9 , respectively. This work demonstrates the potential of all-inorganic lead-free halide perovskite-based heterostructures for photocatalytic organic reactions.