Nitrogen-doped carbon dots (N-CDs), derived from the biomass (anthocyanin), are the novel additive to the nanocarbon materials, which is expected to bring a wide spectrum of novel applications. Moreover, metallic oxides are emerging for their unique potential for electrocatalysis. Herein, we report the synthesis of N-CDs for the selective detection of Fe³⁺ with a limit of detection of 2.57 μM in the range of 5–60 μM using ethylenediamine and H₂O₂ by a hydrothermal method. The obtained N-CDs displayed a spherical morphology with a particle size range of 2–7 nm and emitted blue luminescence at 394 nm under excitation at 319 nm. Meanwhile, we have demonstrated the fabrication of cost-efficient electrocatalysts for oxygen evolution reaction (OER) in an alkaline medium, employing N-CDs. Owing to the successful incorporation of N-CDs into NiO nanospheres, the resulting N-CDs/NiO with large surface areas, fast charge transfer, and increased conductivity vastly improved the catalytic activity. Remarkably, the optimal of N-CDs/NiO composite requires the overpotential of only 380 mV at a current density of 10 mA cm⁻² and a relatively low Tafel slope of 57.96 mV dec⁻¹ compared with pure NiO. These results open up a facile route for the application of N-CDs and offer prospects for CD-metal hybrids as high OER catalysts in electrochemical energy devices.

源自生物质（花青素）的氮掺杂碳点（N-CDs）是纳米碳材料的新型添加剂，有望带来广泛的新型应用。此外，金属氧化物因其独特的电催化潜力而兴起。在本文中，我们报道了使用乙二胺和H ₂ O ₂选择性检测Fe ³⁺的N-CD的合成，检测限为2.57μM，范围为5-60μM。通过水热法。获得的N-CD呈现球形形态，粒径范围为2–7 nm，并在319 nm激发下在394 nm处发出蓝色发光。同时，我们已经证明了使用N-CD在碱性介质中制备用于氧释放反应（OER）的具有成本效益的电催化剂的方法。由于N-CDs成功地掺入了NiO纳米球中，因此所得的N-CDs / NiO具有大的表面积，快速的电荷转移和增加的电导率，极大地提高了催化活性。值得注意的是，最佳的N-CDs / NiO复合材料在10 mA cm ^-2的电流密度和57.96 mV dec ^-1的相对较低的Tafel斜率下仅需380 mV的过电势。与纯NiO相比。这些结果为N-CD的应用开辟了一条容易的途径，并为CD-金属杂化体作为电化学能源设备中的高OER催化剂提供了前景。