A frogspawn inspired twin MoC/Ni composite with a conductive fibrous network as a robust bifunctional catalyst for advanced anion exchange membrane electrolyzers.

Anion exchange membrane water electrolysis (AEMWE) is considered one of the most cost-effective methods for producing green hydrogen. However, the performance of AEMWE is still restrained by the slow reaction kinetics and poor ion/electron transport of catalysts. Herein, inspired by frogspawn, MoC nanoparticles coupled with Ni were embedded into a N-doped porous carbon nanofiber network (MoC/NCNTs@Ni) by chemical crosslinking electrospinning combined with carbonization. The unique bionic structure can guarantee favorable overall structural flexibility and fast ion/electron transport kinetics. As a result of the robust hydrogen binding energy of MoC, as well as the synergistic impact between Ni and MoC nanoparticles and the conductive network resembling frogspawn, the catalyst developed demonstrates excellent performance in both the HER and OER. When employed as a bifunctional catalyst in water electrolysis, MoC/NCNTs@Ni delivers overpotentials of 155 mV and 320 mV at 10 mA cm for the HER and OER, respectively. In addition, the MoC/NCNTs@Ni also displays excellent long-term durability during a continuous operation test under different currents for 50 h. The assembled AEMWE electrolyzers with MoC/NCNTs@Ni as both the anode and cathode can achieve a current density of 82.5 mA cm at 1.99 V, indicating great potential for industrial water splitting. These results give an insight for the development of advanced bifunctional electrocatalysts for the next generation of green and efficient H production by water electrolysis.