Fast and high-yield synthesis of thiolate Ag44 and Au12Ag32 nanoclusters via the CTAB reverse micelle method

To advance the development of atomically precise Ag and Ag-alloyed nanoclusters, it is critical to develop effective synthetic methods. Herein, we successfully extend the CTAB (cetyl trimethyl ammonium bromide) reverse micelle method to synthesize a high-purity Ag₄₄(p-MBA)₃₀ (p-MBA = para-mercaptobenzoic acid) nanocluster and its corresponding alloy cluster Au₁₂Ag₃₂(p-MBA)₃₀ in a short time (15 min and 5 min), with a high yield of ∼83% and ∼85%, respectively. Furthermore, the mechanism regarding the reverse micelle method has been clearly elucidated. Through characterizing the reaction system by Raman spectroscopy and NMR spectroscopy techniques, it can be revealed that employing CTAB to form reverse micelles to construct a sealed chemical environment is critical for realizing the fast and high-yield synthesis.