Carbon dots (CDs), as emerging zero-dimensional carbon- based nanomaterials, have demonstrated significant potential in

the field of electrocatalytic oxygen reduction reaction (ORR) in recent years. This article systematically reviews the breakthrough

progress in CD preparation techniques and their innovative applications in ORR catalysis. In terms of preparation, the

optimization strategies of top–down methods (arc discharge, laser ablation, electrochemical exfoliation, ultrasonic method)

and bottom-up methods (combustion method, template method, hydrothermal synthesis, microwave-assisted,) are analyzed

in detail. For example, CDs prepared by the nitrogen-doped hydrothermal method achieved a quantum yield of 80%, while

the electrochemical method enabled the controllable preparation of 2.8 nm monodispersed CDs. Regarding ORR applications,

the following findings have been reported: (1) Boron-nitrogen co-doped CDs (BN-CDs) exhibited an onset potential

of 0.985 V and a limiting current density of 4.32 mA cm⁻2, outperforming commercial Pt/C catalysts; (2) Iron-loaded CDs

(Fe-CQDs) had an electron transfer number of 3.96 and a hydrogen peroxide yield of only 2.17% in acidic media; (3) The

fluorine-nitrogen co-doped system (C-GQD) increased the half-wave potential to 0.81 V by modulating the d-band center.

These breakthroughs are attributed to the unique surface defect structure and tunable electron distribution characteristics

of CDs. This review systematically analyzes the performance-enhancing strategies for CD-based electrocatalysts, discusses

existing challenges, such as low yields and unclear catalytic mechanisms; and proposes future development directions

including interface engineering and atomic-level doping. This study provides important theoretical guidance and technical

references for the design of efficient CD-based ORR catalysts.