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.

Photocatalyzed organic transformations have spurred immense interest in synthetic chemistry for the efficient conversion of solar energy into chemical energy. However, the crucial roles of support, which fixes catalytic sites and improves the light-harvesting ability, are often ignored in photoredox transformations. Herein, we report the utilization of spherical SiO₂ support to engineer AuPd alloy particles (denoted as AuPd/SiO₂), conceptually different from traditional methods for tuning optical absorption of plasmonic Au or AuPd particles, to manipulate light-harvesting ability of AuPd particles for highly selective and efficient photocatalytic Suzuki cross-coupling reactions. In this deliberately designed system, typically without the size and shape alternation of AuPd particles, the supported AuPd particles recycle the scattering light from spherical SiO₂ support and achieve the significant broad light-harvesting ability instead of the surface plasmon resonance peak. The engineered AuPd/SiO₂ composites by the use of near-field scattering-promoted optical absorption showcase the remarkably enhanced activity for visible-light-induced photocatalytic Suzuki cross-coupling reactions in comparison with that using commercial SiO₂ support, highlighting the spherical-support-effect induced efficient utilization of scattered light. This work highlights the feasibility of manipulating the light-harvesting capability of bimetallic particles by the near-field scattering-promoted optical absorption model toward efficient photo-driven Suzuki cross-coupling reaction and other C–C coupling organic synthesis to produce high value-added chemicals.