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 (Mo 2 C) embedded in nitrogen-doped carbon (Mo 2 C-Co/N-C) by calcination of H 3 PMo 12 O 40 (PMo 12 )-encapsulated Zn/Co-ZIF at 900 o C, in which the Co and Mo 2 C nanoparticles (NPs) are uniformly encapsulated in porous carbon with a high specific surface area of 315.9 m 2 ·g -1 and a pore volume of 0.68 cm 3 ·g -1 . The as-prepared Mo 2 C-Co/N-C exhibits 99.3% degradation efficiency of 100 ppm of tetracycline (TC) within 20 min in the presence of H 2 O 2 with the reaction rate constant k of 0.211 min -1 , outperforming most reported Fenton-like catalysts. Moreover, the Mo 2 C-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 H 2 O 2 . Simultaneously, the Mo 2 C can accelerate the redox cycle of Co 2+ → Co 3+ → Co 2+ and promote the generation of reactive oxygen species ( 1 O 2 and · OH) which ensured an improved catalytic activity. Mo 2 C-Co/N-C, with bimetallic Mo 2 C-Co nanoparticles embedded in N-doped carbon, enables tetracycline (TC) adsorption and achieves 99.3% TC degradation within 20 minutes via Fenton-like reactions by activating H 2 O 2 to generate 1 O 2 , · OH, and ∙ O 2 - . • A heterostructure of Co and Mo 2 C embedded in nitrogen-doped carbon was prepared. • The Co and Mo 2 C nanoparticles were uniformly wrapped in the porous carbon frame. • The Mo 2 C-Co/N-C showed large specific surface area, abundant porosity and excellent electrical conductivity. • The Mo 2 C-Co/N-C exhibited excellent catalytic degradation of TC. • The mechanism for efficient TC degradation was elucidated.