Photo-Assisted Synthesis of a Pd–Ag@CQD Nanohybrid and Its Catalytic Efficiency in Promoting the Suzuki–Miyaura Cross-Coupling Reaction under Ligand-Free and Ambient Conditions

摘要

Supported bimetallic nanoparticles are very promising heterogeneous catalysts for carbon–carbon cross-coupling reactions, though reports focusing on their synergistic activity for promoting such reactions are very limited. In the current study, bimetallic Pd–Ag hybrid nanoparticles supported on carbon quantum dots (CQDs), Pd–Ag@CQDs, were synthesized by a facile and fast UV-light-driven (365 nm) one-pot protocol for the first time to investigate such a synergistic activity. The physico-chemical structural features of the Pd–Ag@CQD nanohybrid were evaluated by UV–vis, Fourier transform infrared, X-ray diffraction, electron-dispersive X-ray, and transmission electron microscopy analyses. The nanohybrid was found to have dimensions in the range of ca. 3–5 nm. The bimetallic Pd–Ag@CQD nanohybrid was utilized as an efficient heterogeneous catalyst for promoting the Suzuki–Miyaura coupling reaction with aryl bromides and aryl chlorides under ligand-free and ambient conditions. The synergistic activity of the components of the nanohybrid induced catalytic enhancement of the cross-coupling reaction in terms of short reaction times ( 90%). The heterogeneous character of the nanohybrid system also enabled easy separation and recyclability (up to six cycles).