Dual-functional ZnO-templated synthesis of hollow N-doped carbon with atomically dispersed Zn single atoms for electrochemical-colorimetric bimodal H₂O₂ sensing.

ZnO has been used as template to prepare and regulate the structures of functional nanomaterials. Due to the structural characteristics of Zn, its nanomaterials are generally considered inert. This study presents an innovative ZnO-templated synthesis of hollow N-doped carbon materials with atomically dispersed Zn single atoms (Zn SA/NC), where ZnO uniquely serves dual roles as both structural template and Zn precursor. The synthesized Zn SA/NC exhibits remarkable bifunctionality, demonstrating exceptional electrocatalytic activity for H₂O₂ reduction (detection limit: 3.7 µM, sensitivity: 1285.7 µA·mM⁻¹·cm⁻²) and intrinsic peroxidase-like activity for TMB oxidation. Leveraging these properties, we developed a dual-mode H₂O₂ detection platform integrating electrochemical and colorimetric readouts. The work challenges conventional views on Zn's catalytic inertness by revealing that Zn-Nₓ sites enable efficient charge redistribution, while the hollow architecture enhances mass transport. This strategy bridges the gap between structural control and atomic dispersion in single-atom catalyst design.