The enhancement of mass transport and electronic conductivity by nanostructure and electronic configuration tailoring is an efficient strategy to improve electrocatalytic activity and stability for oxygen evolution reactions (OER), and remains a significant challenge to practical applications. Herein, oxygen-incorporated nickel-cobalt phosphide/nitrogen-doped carbon (denoted as NiCoPO/NC) nanosheets were controllably synthesized by utilizing zeolitic imidazolate framework-67 (ZIF-67) as the precursor. This precursor can generate Ni–Co layered double hydroxide/2-methylimidazole (Ni–Co LDH/MeIM) after chemical etching. A subsequent phosphorization process leads to the formation of NiCoPO/NC nanosheets, which possess both nitrogen-doped carbon and incorporated P/O elements in the hybrid structure. As expected, due to the resulting structural and compositional characteristics, the NiCoPO/NC nanosheets exhibit superior electrocatalytic activity with an overpotential of 300 mV at 10 mA cm−2 and excellent long-term stability, comparable to commercial RuO2 and NiCoPO/NC nanocages. The facile and controllable synthetic method paves the way for synthesis of other two-dimensional nanomaterials for energy and environment-related applications.