Carbon dots (CDs) have become an emerging carbon nanomaterial for use in energy-conversion systems because of their large surface area and rapid electron transfer. Carbon dots (BN-CDs) doped with both boron and nitrogen were synthesized by a simple one-step electrochemical etching approach using low-cost petroleum coke as precursor. Compared with CDs doped with only B or N, BN-CDs showed an excellent four-electron oxygen reduction reaction (ORR) activity with a positive onset potential of 0.958 V and a large diffusion-limited current density of −4.32 mA cm⁻². Furthermore, the long-term stability and methanol tolerance of BN-CDs were better than those of a commercial Pt/C catalyst. It was found by density functional theory (DFT) calculation that the co-doping of N and B promoted the adsorption of O₂ molecules in the ORR process. This work provides new insight into the rational design of carbon nanomaterials and their use in energy conversion.

碳点（CD）由于其表面积大和电子转移速度快，已成为用于能量转换系统的新兴碳纳米材料。使用低成本石油焦作为前驱体，通过简单的一步电化学蚀刻方法合成了掺杂硼和氮的碳点 (BN-CD)。与仅掺杂 B 或 N 的 CD 相比，BN-CD 显示出优异的四电子氧还原反应 (ORR) 活性，正起始电位为 0.958 V，扩散限制电流密度为 -4.32 mA cm ^-2。此外，BN-CDs 的长期稳定性和甲醇耐受性优于商业 Pt/C 催化剂。通过密度泛函理论（DFT）计算发现，N和B的共掺杂促进了O的吸附ORR 过程中的_{2 个}分子。这项工作为碳纳米材料的合理设计及其在能量转换中的应用提供了新的见解。