Ultrasonically Driven Structural Evolution of Bimetallic Heterostructures for Construction of an ElectroTrace Analyzer

Bimetallic heterostructure materials (BHMs) have garnered significant attention due to their exceptional synergistic electrocatalytic properties. However, challenges persist in developing precise, scalable synthetic methods and understanding their underlying mechanisms. Here, we develop an ultrasonic-assisted anchoring strategy to fabricate BHMs on multiwalled carbon nanotubes (MWCNTs). First, a multifunctional polyaromatic organic receptor (MPOR), featuring urea and imine functional groups, was physisorbed onto MWCNTs (MWCNTs@MPOR), inducing structural coiling. Subsequent interaction with Hg metal ions led to the reorganization of MWCNTs (MWCNTs@MPOR/Hg), followed by ultrasonic treatment that facilitated Mn ion anchoring at the free imine sites, yielding the final BHMs MWCNTs@MPOR/Hg/Mn. Notably, the structural changes and nature of interactions were thoroughly studied by density functional theory (DFT) simulations. Experimental results and first-principles calculations revealed remarkably enhanced electrochemical activity with a charge transfer of -0.179e in MWCNTs@MPOR/Hg/Mn. Further, we introduced a portable "ElectroTrace Analyzer" based on MWCNTs@MPOR/Hg/Mn for real-time detection and quantification of atrazine (herbicide). Our ultrasonically assisted strategy for BHM synthesis offers a fascinating avenue for the advanced development of useful BHMs for real-world applications.