Bimetallic MOF-derived hierarchical porous carbon spheres for electrochemical Cu2+ sensing

Abstract

The development of detection devices with rapid response, high sensitivity, and precise detection capabilities for heavy metal ions remains a research hotspot in environmental protection and food safety. In this study, a facile and efficient synchronous doping/etching strategy was employed to synthesize hierarchically porous bimetallic MOF-derived CeSn@C-10 material. Comprehensive characterization techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed that the incorporation of Sn species significantly enhanced oxygen vacancy concentration in the CeO₂ lattice while stabilizing low-valent Ce³⁺ species, thereby boosting the electrocatalytic activity for CeSn@C-10. The hierarchical porous architecture endowed the material with an enlarged specific surface area and improved accessibility to active sites. When fabricated into an electrochemical sensor (CeSn@C-10/GCE), it exhibited exceptional Cu²⁺ detection performance with dual linear ranges of 0.2–5 μM and 5–60 μM, achieving a low detection limit of 38 nM (S/N = 3). The sensor demonstrated remarkable anti-interference capability and promising applicability in real-sample analysis. This work provides a novel strategy for designing hierarchically porous bimetallic electrochemical sensors through synergistic enhancement mechanisms.