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.Keywords: In2S3; Photoredox dual reaction; Hydrogen evolution; Visible light; Hole cocatalyst.