Ternary FeCo2Mo5 Oxyhydroxide Nanosheets Integrate on the Surface-Vulcanized Ni Foam for Excellent Electrocatalytic Oxygen Evolution

Earth-abundant first-row transition-metal-based electrocatalysts with a large current density for water splitting are pivotal to give impetus to large-scale utilization of hydrogen energy. However, the operating potential is significantly larger than the thermodynamic requirements. Herein, the ternary FeCo2Mo5 layered double hydroxide (LDH) nanosheets grown on the surface of a vulcanized Ni foam (FeCo2Mo5 LDH/ Ni3S2/NF) are proposed to improve the mass and electron transport for driving the oxygen evolution reaction (OER), where the integrated hierarchical structure configurations contribute rich active sites and a large electrode/electrolyte interface for mass transfer, and the construction of a Ni3S2/NF heterojunction can facilitate electron mobility from the surface to the inner region, leading to a high valence of FeCo2Mo5 LDH with favorable OER kinetics. Therefore, the catalyst exhibits excellent OER activity with the ultralow overpotential of 128 and 300 mV at the current density of 10 and 100 mA cm(-2) in 1 M KOH and activity retention over 12 h at 95 mA cm(-2). This research may enable a large extension toward the design of cheap and highly efficient practical catalytic electrodes for water splitting.

Automated summary

By growing ternary FeCo2Mo5 LDH nanosheets on the surface of vulcanized Ni foam, the mass and electron transport for the oxygen evolution reaction (OER) can be improved. This research has important implications for the design of cheap and efficient catalytic electrodes.