Magnetic reinforcement of electrocatalytic HER performance on Keplerate polyoxomolybdate-derived multi-interfacial FeMo/Mo2C@C catalyst

Electrocatalysis is a promising approach for sustainable hydrogen generation, and the exploration of effective electrocatalysts for hydrogen evolution reactions (HER) is of great significance for exploiting and utilizing renewable energy. Herein, the magnetic FeMo/Mo 2 C@C composites with multi-heterostructure interfaces and hierarchical structure are first designed and fabricated via molybdenum blue preassembly strategy by using Keplerate polyoxomolybdate {Mo 72 Fe 30 } and melamine as precursors. Benefiting from its unique characteristics, FeMo/Mo 2 C@C catalyst exhibits superior HER electrocatalytic activity than pure Mo 2 C@C. Interestingly, the optimized FeMo/Mo 2 C@C presents the HER magnetic reinforcement by simply applying an magnetic field, characteristic of 97 mV@10 mA cm –2 , 201 mV@50 mA cm –2 , and a robust durability for more than 18 h, which are 120 and 85 mV less than that of FeMo/Mo 2 C@C without magnetization, and greatly lower than comparative Mo 2 C@C catalyst (272 mV@10 mA cm –2 and 396 mV@50 mA cm –2 ). This may be attributed to that the FeMo/Mo 2 C@C can afford fast electrons transmitting from electrode to active sites during HER process when imposing an external magnetic field. This work offers a novel design direction to develop magnetic transition metal based-materials for electrochemical applications and paves a new way to utilize the magnetic enhancement to further improve the hydrogen evolution performance.