MoS2 decorated CdS composite catalyst for photoredox-mediated C–N coupling of amines to imines and hydrogen production

Simultaneous utilization of photogenerated electrons and holes within a photoredox system enables effective hydrogen (H2) production and organic synthesis, aligning with eco-friendly chemistry principles and current energy challenges. Here, we report the preparation and application of cocatalyst MoS2 decorated CdS (MoS2CdS) composites for the photoredox-mediated C–N coupling of amines to imines and H2 generation under visible light illumination. The H2 and N-benzylidenebenzylamine yields for the optimal MoS2CdS are 28.9 and 15.0 times higher than those of bare CdS, respectively. Mechanism studies reveal that the enhanced photocatalytic activity results from the MoS2 acting as an electron sink, which accelerates the separation and migration of photogenerated charge carriers. Additionally, the pH(•CH)NH2 intermediates are found to play a pivotal role in the dehydrogenative coupling of benzylamine. Furthermore, the MoS2CdS composites exhibit universal applicability in the conversion of various aromatic amines into corresponding imines integrated with H2 evolution.