Bimetallic Mo₂C-Co Nanoparticles Embedded in Nitrogen-Doped Carbon Heterostructures as an Efficient Fenton-like Catalyst for Antibiotics Degradation

Fenton and Fenton-like catalysts have demonstrated great potential in the field of antibiotic degradation. However, it remains a challenge to remove the high concentrations of antibiotics effectively over a wide range of pH values. Herein, we successfully fabricate a heterostructure of cobalt (Co) and molybdenum carbide (Mo₂C) embedded in nitrogen-doped carbon (Mo₂C-Co/N-C) by calcination of H₃PMo₁₂O₄₀ (PMo₁₂)-encapsulated Zn/Co-ZIF at 900 ^oC, in which the Co and Mo₂C nanoparticles (NPs) are uniformly encapsulated in porous carbon with a high specific surface area of 315.9 m²·g^-1 and a pore volume of 0.68 cm³·g^-1. The as-prepared Mo₂C-Co/N-C exhibits 99.3% degradation efficiency of 100 ppm of tetracycline (TC) within 20 min in the presence of H₂O₂ with the reaction rate constant k of 0.211 min^-1, outperforming most reported Fenton-like catalysts. Moreover, the Mo₂C-Co/N-C achieved above 90% removal efficiency for TC at concentrations up to 100 ppm over a wide range of pH values (3.0–9.0) and can also be recycled ten times without an obvious decrease in degradation efficiency, indicating satisfactory reusability and stability. Comprehensive studies demonstrated that the loss of electrons in Co species enhances the specific adsorption of TC and H₂O₂. Simultaneously, the Mo₂C can accelerate the redox cycle of Co²⁺ → Co³⁺ → Co²⁺ and promote the generation of reactive oxygen species (¹O₂ and ^· OH) which ensured an improved catalytic activity.