Bimetallic organic framework derived Co-MoxN/Mo2C catalyst for HER/OER bifunctional electrocatalytic reaction

Abstract

• A novel bimetallic MOFs with a stable and special framework structure was developed. • Framework structure solved problem of easy aggregation and collapse of Mo 2 C material. • High specific surface area 3D Co-Mo x N/Mo 2 C provide more HER/OER catalytic active sites. Metal organic frameworks (MOFs) are widely used as precursors due to their tunable morphology and high specific surface area. Molybdenum nitride (MoN) and molybdenum carbide (Mo 2 C) are promising catalyst materials with electronic structures similar to the noble metal platinum. However, the preparation and modification of the composite systems comprising MoN and Mo 2 C are complex, often leading to significant agglomeration and limiting their application in various catalytic fields. In this work, we designed and developed a novel bimetallic Co-MOFs-Mo with a stable and unique framework morphology. By varying the organic ligand content, we controlled the morphology and enhanced the intrinsic electrocatalytic activity through Mo doping. Using the Co-MOFs-Mo sample as the Co source, we fabricated a Co-Mo x N/Mo 2 C catalytic material with a special framework structure. Compared to Mo 2 N and Mo 2 N/Mo 2 C, this catalyst exhibits a larger specific surface area and superior performance in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The Co-Mo x N/Mo 2 C catalyst achieves an HER overpotential of 297 mV at a current density of 10 mA·cm −2 and an OER overpotential of 480 mV at 20 mA·cm −2 . This research provides valuable insights into the rational design of molybdenum-based noble-metal-free catalyst materials.