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