Preparation of MnOx/CC Electrode by One-Step Electrodeposition for Electrochemical Detection of Cd2+ in Water

Transition metal oxides (e.g., MnO_x) can effectively promote the redox reactions of heavy metal ions through abundant valence changes. However, relatively few studies have been conducted on the application of MnO_x for the detection of Cd²⁺ without pre-enrichment conditions. For this reason, in this study, MnO_x was grown in situ on a carbon cloth substrate by one-step electrodeposition. The effect of the valence composition of MnO_x and its variation on the Cd²⁺ without pre-enrichment detection performance was systematically investigated. The morphology, structure, and chemical composition of the materials were fully characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that the deposition of MnO_x not only significantly increased the active surface area of the electrodes but also facilitated electron transfer through the valence transition of Mn²⁺/Mn³⁺↔Mn³⁺/Mn⁴⁺. The detection of Cd²⁺ in water samples can be successfully achieved without pre-enrichment, and the electrode has good stability and reproducibility. This study provides a new design idea for applying MnO_x electrodes in Cd²⁺ detection without pre-enrichment and provides a reference for further optimization of electrochemical sensors.