Abstract High-efficiency and environmental electro-catalyst are prepared for the water oxidation. Here, we report nitrogen doping‑carbon quantum dot (N-CQD) that is prepared from field bindweed using the hydrothermal method. Also, NiCo-layered double hydroxide (LDH) was prepared using a simple method. The prepared samples were characterized using several techniques that confirmed the successful preparation of N-CQD and NiCo-LDH. Also, the effect of molar ratios of Ni: Co on the morphology of NiCo-LDH were studied by the Field Emission-Scanning Electron Microscopy (FE-SEM). The obtained images obviously reveal that apply several molar ratios of Ni and Co can affect the morphology and optimized molar ratio Ni: Co was 1: 1. Then, we use N-CQDs combination with the optimized NiCo-LDH for water oxidation. The resulting NiCo-LDH/N-CQD shows improved electro-catalytic activity in comparison with pure NiCo-LDH (with an onset-potential of 1.55 V (vs. RHE) and overpotential about ~ 325 mV in neutral media) for oxygen evolution. The enhanced water oxidation activity is attributed to the association of the NiCo-LDH with N-CQDs. N-CQDs which supply rapid electron transfer, supreme conductivity, and electron reservoir characters that are caused to the rapid electron transfers from N-CQDs to NiCo-LDH on the surface and consequently, could further increase the electro-catalytic reaction.

中文翻译：

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使用田间旋花和镍钴层状双氢氧化物改善中性 pH 值下的水氧化

摘要 制备了高效、环保的水氧化电催化剂。在这里，我们报告了使用水热法从田间旋花制备的氮掺杂碳量子点 (N-CQD)。此外，NiCo 层状双氢氧化物 (LDH) 是使用简单的方法制备的。制备的样品使用多种技术进行表征，这些技术证实了 N-CQD 和 NiCo-LDH 的成功制备。此外，通过场发射扫描电子显微镜 (FE-SEM) 研究了 Ni: Co 摩尔比对 NiCo-LDH 形态的影响。获得的图像明显表明，应用多种 Ni 和 Co 摩尔比会影响形态，优化的 Ni：Co 摩尔比为 1：1。然后，我们使用 N-CQDs 与优化的 NiCo-LDH 组合进行水氧化。与纯 NiCo-LDH 相比，所得的 NiCo-LDH/N-CQD 显示出改善的电催化活性（起始电位为 1.55 V（相对于 RHE），在中性介质中的过电位约为 325 mV）用于析氧。增强的水氧化活性归因于 NiCo-LDH 与 N-CQD 的结合。N-CQDs 提供快速的电子转移、卓越的导电性和电子储库特性，这些特性导致电子从 N-CQDs 快速转移到表面的 NiCo-LDH，从而进一步增加电催化反应。