Tailored Design of Trimetallic Mesoporous Au–Ag–Cu Alloys for Maximizing Electrochemical Applications

This study reports a one-step electrodeposition of ternary mesoporous gold-silver-copper (mAuAgCu) alloy films by using diblock copolymers as pore-directing agents. Additionally, it examines the effects of alloy composition on the electrocatalytic performance of mAuAgCu thin films. Using advanced characterization techniques, such as scanning transmission electron microscopy and X-ray photoelectron spectroscopy, the interplay between alloy composition, surface structure, and catalytic performance is revealed. The optimized mAu(0.60)Ag(0.20)Cu(0.20) alloy (prepared from the precursor solution with an Au:Ag:Cu ratio of 60:20:20) demonstrates the highest catalytic activity for glucose sensing. This is because the introduction of Cu facilitates a uniform distribution of defects in this mesoporous ternary alloy through controlled reduction, leading to a higher electrochemically active surface area (ECSA) and more active sites for electrochemical reactions. This research provides valuable insights into designing trimetallic alloys, demonstrating how the surface structure and alloy composition can control the catalytic performance for electrochemical applications.