Exploiting effective and low-cost electrocatalysts toward water oxidation is of vital significance for boosting overall water splitting. Herein, we proposed a simple method for constructing dendritic N-doped carbon/ manganese oxides (N-C/MnO_x) hybrid nanocomposites by annealing the composite of nitrogen-doped carbon quantum dots (N-CQDs) and γ-MnOOH (γ-MnOOH@N-CQDs) at different temperatures under N₂/O₂ atmosphere. The obtained N-C/MnO_x exhibited remarkable electrocatalytic activity and stability for oxygen evolution reaction (OER) owing to their unique dendritic structure, rich oxygen vacancies, optimized electronic structure, abundant Mn-C/N, and large electrochemical active area. Among of the prepared N-C/MnO_x hybrid nanocomposites, N-C/Mn₂O₃ showed the best performance toward OER with an overpotential of merely 347 mV to reach to 10 mA cm⁻², along with a small Tafel slope of 75.51 mV dec⁻¹. More remarkably, by combining Pt/C with N-C/Mn₂O₃ for overall water splitting, a battery voltage of only 1.67 V is needed to reach the 10 mA cm⁻², rivaling the activity of the state-of-the-art IrO₂ ‖ Pt/C couple.

利用有效且低成本的电催化剂进行水氧化对于促进整体水分解具有重要意义。在此，我们提出了一种简单的方法用于构建树枝状掺杂的N-碳/锰氧化物（NC / MnO的_X）混合纳米复合材料通过退火复合氮掺杂的碳的量子点（N-CQDs）和γ-MnOOH（锰γ-MnOOH的的@ N-CQDs) 在 N ₂ /O ₂气氛下的不同温度。由于其独特的树枝状结构、丰富的氧空位、优化的电子结构、丰富的Mn-C/N和大的电化学活性面积，所获得的NC/MnO _x对析氧反应（OER）表现出显着的电催化活性和稳定性。其中制备的 NC/MnO _x在混合纳米复合材料中，NC/Mn ₂ O ₃表现出对 OER 的最佳性能，其过电位仅为 347 mV，可达到 10 mA cm ^-2，以及 75.51 mV dec ^-1的小塔菲尔斜率。更值得注意的是，通过将 Pt/C 与 NC/Mn ₂ O _{3 结合}用于整体水分解，仅需 1.67 V 的电池电压即可达到 10 mA cm ^-2，可与最先进的活性相媲美IrO ₂ ‖ Pt/C 对。