Nanoarchitected MoS₂/gold nanoparticles thin films: one-step synthesis, mechanistic insights and electrocatalytic...

We report a direct, one-pot and one-step synthesis of nanoarchitectures composed of molybdenum disulfide (MoS₂) and gold nanoparticles (AuNPs), along with mechanistic insights into the reaction pathway. A spontaneous reaction between exfoliated MoS₂ and aqueous solution of HAuCl₄ was driven at the interface between two immiscible liquids, producing thin, transparent, homogeneous, and colorful films. By adjusting the reaction time and precursor ratios, we successfully created nanoarchitectures comprising AuNPs and a mixture of 2H- and 1T-MoS₂ structures. Supported by different characterization techniques, we propose a reaction mechanism based on the partial oxidation of Mo(iv) associated with the reduction of the gold precursor to metallic gold. These materials exhibit tunable MoS₂ interlayer distances and an increased density of defects, making them promising candidates for catalytic applications in the hydrogen evolution reaction. Electrochemical characterization revealed an overpotential 45% lower for MoS₂/AuNPs nanoarchitectures than that observed for pristine MoS₂.