Efficient detection of chemical oxygen demand (COD) is crucial for effective pollution prevention. Traditional Cu-based electrodes, widely utilized for COD sensors suffer from issues related to low activity and stability. This study introduced a novel approach by employing a copper foam-supported metal-organic frameworks (Cu-MOF), synthesized through a solvothermal method, which is subsequently pyrolyzed to yield a carbon-capsulated CuO_x/Cu foam electrode. Cyclic voltammetry analysis demonstrated that the carbon-capsulated CuO_x/Cu foam electrode exhibited superior redox activity, notably generating an increased amount of Cu(III) species. This enhancement significantly contributed to the electrocatalytic oxidation of organic compounds. The developed electrode demonstrated a wide linear detection range of 5–600 ppm, with a low detection limit of 0.96 ppm (S/N=3) for COD sensing. Notably, the sensor exhibited excellent anti-interference capabilities, desirable reproducibility, and stability. The proposed method was successfully applied to determine COD in real water samples. Comparative analysis with the standard potassium dichromate method revealed high accuracy and a low relative error (2.89 %–6.72 %). This innovative approach holds promise for rapid and accurate COD detection, presenting a valuable contribution to environmental monitoring and water quality assessment.

中文翻译：

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由泡沫铜支撑的 Cu-MOF 衍生的碳封装 CuOx 对化学需氧量进行高灵敏电化学测定

化学需氧量（COD）的高效检测对于有效预防污染至关重要。广泛用于 COD 传感器的传统铜基电极存在活性低和稳定性低的问题。这项研究引入了一种新方法，采用泡沫铜支撑的金属有机框架（Cu-MOF），通过溶剂热法合成，随后热解产生碳封装的 CuO _x /Cu 泡沫电极。循环伏安分析表明，碳包覆的 CuO _x /Cu 泡沫电极表现出优异的氧化还原活性，特别是产生了更多的 Cu(III) 物质。这种增强显着促进了有机化合物的电催化氧化。开发的电极具有 5-600 ppm 的宽线性检测范围，COD 传感的检测限低至 0.96 ppm (S/N=3)。值得注意的是，该传感器表现出优异的抗干扰能力、良好的再现性和稳定性。该方法已成功应用于实际水样中COD的测定。与标准重铬酸钾法的比较分析表明，准确度高，相对误差低（2.89%~6.72%）。这种创新方法有望实现快速、准确的 COD 检测，为环境监测和水质评估做出宝贵贡献。