Construction of NiFe₂O₄/Fe₂O₃@Ni(OH)₂ hollow core–shell nanotubes based on metal–organic frameworks for efficient oxygen evolution electrocatalysis

The exploration of affordable, efficient, and stable electrocatalysts with commensurate oxygen evolution reaction (OER) performance is a significant focus of research. In this work, NiFe₂O₄/Fe₂O₃@Ni(OH)₂ hollow core–shell nanotubes (NiFe₂O₄/Fe₂O₃@Ni(OH)₂ HCSNs) were synthesized by a metal–organic frameworks (MOFs) engaged strategy. The hollow porous structure derived from MOFs, along with the synergistic effect of NiFe₂O₄/Fe₂O₃ hollow nanotubes (HNs) and Ni(OH)₂ nanosheets (NSs), provides abundant accessible electroactive sites and facilitates rapid electron transport. As a result, the optimized NiFe₂O₄/Fe₂O₃@Ni(OH)₂-3 HCSNs exhibit remarkable OER performance, demonstrating a low overpotential of 246 mV at 10 mA cm⁻² and significant stability. Furthermore, an overpotential of only 340 mV is needed to reach 10 mA cm⁻² in simulated seawater electrolysis (1.0 M KOH + 0.5 M NaCl) and remains stable for 70000 s. We anticipated that this work could pave the way for the development of efficient non-noble-metal electrodes for the OER.