Developing metal oxide catalysts with comparable activity to precious metals has become a hot but challenging area of research for wastewater purification. Herein, CoOx particles and nitrogen co-doped carbon with a hierarchical structure were designed and synthesized via a temperature-controlled pyrolysis strategy using inert Co-based metal–organic frameworks (Co-MOFs) as precursors. Unlike traditional methods, the exquisite pyrolysis of the Co-MOF at 400 °C enabling the CoOx particles with an average diameter of 6.8 nm to uniformly disperse, thus facilitating the formation of the optimized CoOx/CN-400 composite. Benefiting from the unique morphology and composition, CoOx/CN-400 exhibited improved redox property and exceptional activity for the reduction of nitrophenol to form the corresponding aminophenol compounds. The complete conversion of 4-nitrophenol over CoOx/CN-400 requires only 35 min with a rate constant of 0.12 min−1, which is significantly higher than that of most non-noble metal catalysts and approaching some of the noble metal-based catalysts. Furthermore, leveraging the embedded CoOx particles, CoOx/CN-400 maintains its high catalytic efficiency even after six successive cycles, demonstrates an outstanding long-term catalytic capability and reusability. Finally, the mechanisms of 4-NP reduction have been hypothesized based on the combination of characterization and DTF calculations.