Preparation of MnO(x)/CC Electrode by One-Step Electrodeposition for Electrochemical Detection of Cd(2+) 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 Cd(2+) 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 Cd(2+) 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 Mn(2+)/Mn(3+)↔Mn(3+)/Mn(4+). The detection of Cd(2+) 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 Cd(2+) detection without pre-enrichment and provides a reference for further optimization of electrochemical sensors.