Synergistic mesoporous bimetallic gold-silver nanoparticles: Synthesis, structure, and superior electrocatalytic activity

Abstract

Mesoporous bimetallic nanoparticles have gained immense interest due to their unique properties and applications in various fields. In this study, we report a novel and straightforward one-pot chemical reduction method for the synthesis of mesoporous AuAg nanoparticles, featuring a substantial mesopore size (>10 nm) and a well-defined structure. The synthetic route involves employing L-cysteine as a ligand to form thiolate-metal(I) complexes and co-reduction of metal precursors around sacrificial templates of polymeric micelles. The resulting nanoparticles exhibit remarkable uniformity in size and possess a well-ordered mesoporous structure. Structural analyses confirm the formation of an alloy system containing Au and Ag without any distinct phases. By adjusting the initial precursor composition, precise control over the Au:Ag ratios in the final products is achievable. The electrocatalytic activity of mesoporous AuAg nanoparticles in the electrooxidation of small molecules surpasses that of mesoporous Au nanoparticles, owing to the synergistic effect arising from both the alterations in the electronic structure and the benefits offered by the porous architecture. This synthetic approach provides a promising avenue for developing efficient and cost-effective mesoporous Au-based nanoparticles for a diverse range of applications.