Research on Electrochemical Deposition CeO2 Hydroxyl Radical Sensor

• 1、Dalian University of Technology School of Integrated Circuits

Abstract：Hydroxyl radicals ( OH) have extremely strong oxidation ability and are often used to clean harmful organic substances such as organic wastewater, pesticides on fruit and vegetable surfaces, and bacteria. Due to its short lifespan and high activity, simple and accurate detection of it is a challenge. This article describes the electrochemical deposition of cerium oxide (CeO2) thin films on an Au electrode using cathodic constant current polarization to obtain an electrochemical sensor based on CeO2, and to detect OH generated by Fenton reagent. The test results show that CeO2 at different current densities has a linear response to OH detection, but due to issues such as film thickness, conductivity, and binding sites, there are significant differences in response sensitivity. The sample exhibits the best sensing characteristics at a current density of -0.15 mA/cm2. Its sensitivity is 10.455 μ A/mmol. The CeO2 electrochemical sensor has a wide linear range (1-9 mmol/L) for the detection of OH, and can maintain a linear response at a resolution of 0.25 mmol/L. After 30 days of storage, long-term stability testing was conducted, and the response sensitivity decreased to 6.388 μ A/mmol, but the response maintains a basic linear relationship.

Keywords： CeO2 Hydroxyl radicals Electrochemical deposition Electrochemical sensors