This work reports the synthesis of copper- and cobalt-based coupled and mixed metal oxides (CuO-Co3O4 and CuCo2O4, respectively) utilizing a simple hydrothermal and calcination approach. CuO-Co3O4, CuCo2O4, and the control samples were characterized by powder X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray, and X-ray photoelectron spectroscopy. TEM and FE-SEM analyses of CuO-Co3O4 reveal the presence of two distinct morphologies: rod- and sphere-shaped particles (CuO and Co3O4, respectively). Further, CuO-Co3O4 was efficiently utilized as an electrocatalyst for the selective oxidation of hydrazine (Hyz). CuO-Co3O4 shows a high redox response compared to CuO, Co3O4, CuCo2O4, and the physical mixture of CuO and Co3O4 (CuO/Co3O4). This enhanced performance is attributed to the synergistic interaction between the metal ions caused by their close proximity and the increased exposure of surface active sites. CuO-Co3O4 shows a broad linear range (1–3500 µM), a low detection limit (0.29 µM), and high sensitivity (0.5756 µA µM-1 cm-2) for the Hyz determination. Kinetic parameters, for instance the diffusion coefficient and catalytic rate constant for Hyz oxidation were obtained using chronoamperometry. Additionally, CuO-Co3O4 was effectively utilized to analyze Hyz in real samples with acceptable recovery rates.

中文翻译：

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偶联 （CuO-Co3O4） 与混合 （CuCo2O4） 金属氧化物电催化效率的比较研究：通过肼氧化和灵敏测定进行探测


这项工作报道了利用简单的水热和煅烧方法合成铜基和钴基耦合金属氧化物和混合金属氧化物（分别为 CuO-Co3O4 和 CuCo2O4）。采用粉末 X 射线衍射 （XRD）、高分辨率透射电子显微镜 （HR-TEM）、场发射扫描电子显微镜 （FE-SEM）、能量色散 X 射线和 X 射线光电子能谱对 CuO-Co3O4、CuCo2O4 和对照样品进行了表征。CuO-Co3O4 的 TEM 和 FE-SEM 分析揭示了两种不同形态的存在：棒状和球形颗粒（分别为 CuO 和 Co3O4）。此外，CuO-Co3O4 被有效地用作肼 （Hyz） 选择性氧化的电催化剂。与 CuO、Co3O4、CuCo2O4 以及 CuO 和 Co3O4 的物理混合物 （CuO/Co3O4） 相比，CuO-Co3O4 显示出高氧化还原响应。这种增强的性能归因于金属离子之间的协同相互作用，因为它们非常接近，并且表面活性位点的暴露增加。CuO-Co3O4 在 Hyz 测定中显示出较宽的线性范围 （1–3500 μM）、低检测限 （0.29 μM） 和高灵敏度 （0.5756 μA μM-1 cm-2）。动力学参数，例如 Hyz 氧化的扩散系数和催化速率常数，是使用计时安培法获得的。此外，CuO-Co3O4 被有效地用于分析真实样品中的 Hyz，回收率可接受。