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In this work, we demonstrate that the incorporation of MoS2 nanosheets with Pd nanodots is a promising way for promoting the visible-light-induced Suzuki–Miyaura C–C coupling reaction. The MoS2 nanosheets decorated with Pd nanodots showed very high photocatalytic activity. The turnover frequency for the biphenyl product was >1600 h−1 even under sunlight illumination at room temperature. Mechanistic studies show that the high catalytic activity originated from the efficient electron–hole pair generation mechanism of MoS2 under visible-light illumination instead of purely thermal effects.

Plasmonic nanostructures can be employed for performing photocatalytic reactions with visible-light illumination involving two different possible mechanisms, namely, the near-field enhancement and/or direct hot-electron transfer to the conduction band of an active catalyst. In this study, we demonstrate the significant contribution of a graphene interface layer present between plasmonic nanoparticles and active catalysts (Pd nanodots) in enhancing the photocatalytic efficiency of Pd nanodots through an accelerated electron transfer process. The well-defined Pd-nanodot-modified gold nanoparticles with or without a graphene interface layer were prepared using a wet-chemical synthetic method. The role of the graphene interface was investigated by performing wavelength-dependent reduction studies using potassium hexacyanoferrate (III) in the presence of Pd-nanodot-modified cysteamine-modified AuNPs (Pd-cys-AuNPs), Pd-nanodot-modified graphene oxide (GO)-coated AuNPs (Pd-GO-AuNPs), and Pd-nanodot-modified reduced GO (rGO)-coated AuNPs (Pd-rGO-AuNPs). The fastest rate for the reduction of Fe3+ to Fe2+ was obtained with Pd-rGO-AuNPs because of the fast electron transfer achieved in the presence of the reduced graphene oxide layer. The highest catalytic activity for the visible-light induced C-C coupling reaction was obtained with Pd-rGO-AuNPs, indicating the role of the graphene interface layer. These results indicate that the design and use of engineered interfaces are of importance to achieve enhanced catalytic activity with plasmonic hybrid nanomaterials.