A novel electrochemical sensor based on CuO-CeO2/MXene nanocomposite for quantitative and continuous detection of H2O2

In this study, a sensitive and stable electrochemical sensor based on CuO-CeO2/MXene is constructed for the continuous detection of H2O2. CuO-CeO2 nanomaterials are applied as a catalyst to promote the electrolysis of H2O2 on the electrode surface as well as amplify the reduction current for the aim of H2O2 detection. MXene serves as a catalyst carrier for CuO-CeO2 and enhances the electron transfer rate during the reduction process of H2O2. Furthermore, the generation of hydroxyl radical during the decomposition of H2O2 is demonstrated by UV -vis spectrum and first-principles calculation to explore the reaction mechanism. The electrolysis rate of H2O2 is obtained as 0.61 x 10(3) M-1 s(-1) by chronoamperometry. Based on the good properties, the electrochemical sensor fabricated by CuO-CeO2/MXene exhibits high sensitivity, stability, and reproducibility. A good linear relationship is ranged from 5.0 mu M to 100 mu M with a low detection limit of 1.67 mu M for H2O2 detection. Besides, the current signal is stable and reproducible when continuously testing H2O2 content, which can calculate a reliable H2O2 concentration value for practical application. The proposed approach sheds light on the rational design and assembly of electrochemical sensors and its relevant catalytic mechanism study.