Cocatalyst-modified In₂S₃ photocatalysts for C–N coupling of amines integrated with H₂ evolution

Photocatalytic hydrogen (H₂) production coupled with selective oxidation of organic compounds into high-value-added organic intermediates has expansive prospects in the utilization and transformation of solar energy, which meets the development requirements of green chemistry. In this work, high-efficiency hole cocatalyst PdS-decorated In₂S₃ flower-like microspheres are fabricated for the effective visible-light-driven C–N coupling of amines to imines coupled with H₂ evolution. Owing to the establishment of the internal electric field, which further boosts the transfer of photoexcited holes to PdS, PdS–In₂S₃ exhibits distinctly enhanced photocatalytic redox performance, which is 39.8 times higher for H₂ and 14.3 times higher for N-benzylidenebenzylamine than that of the blank In2S3, along with high selectivity and stability. Furthermore, the practicability of dehydrogenation coupling of various aromatic amines to the corresponding C–N coupling products on PdS–In₂S₃ has been demonstrated and a plausible reaction mechanism has been proposed. This work is anticipated to stimulate further interest in establishing an innovative photoredox platform for selective organic synthesis coupled with H₂ evolution in a green and sustainable way.