LAUSR

Abstract Design and synthesis of highly effective catalysts for electrochemical oxygen reduction reaction (ORR) with low cost is of great significance due to the purpose of energy conversion and storage. Herein, we report a facile solvothermal method to prepare ultrafine cobalt phosphide (CoPx)-doped Co-based zeolitic imidazole framework (CoPx/ZIF-67). The one-pot synthesis of CoPx/ZIF-67 involves an oxygen-free sealed room-temperature reaction, in which the high chemical activity of rich defect sits in 2D black phosphorus quantum dots (BPQDs) endows edge-selective coordination /reduction of Co ions. Carbonization of CoPx/ZIF-67 at 800 °C can produce CoPx-N-doped porous carbon composites (CoPx-NPC). The as-prepared CoPx-NPC retains the intrinsic morphology of rhombic dodecahedrons, similar to that of NPC derived from ZIF-67. The ultrafine CoPx doping causes chemical and electronic modulation and offers more active electrocatalytic sites etc., so that CoPx-NPC possesses enhanced ORR performance in terms of positive onset-potential (∼−0.06 V vs. SCE), large diffusion limiting current density (−4.703 mA cm−2), high stability, as well as the accelerated reaction kinetics.