Nickel-iron-cobalt (hydr)oxide-decorated carbon nanotube forest for the oxygen-evolution reaction.

In this study, an oxygen-evolution reaction (OER) electrocatalyst was developed by first growing a vertically aligned carbon nanotube forest (CNT F), and a NiFeCo (hydr)oxide coating was co-electrodeposited onto the CNT forest. X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy confirm that the metal (hydr)oxide is distributed across the high-surface-area CNT scaffold. The performance is attributed to the synergy between the multi-metal (hydr)oxide supported on CNT F, which together provide abundant active sites, efficient charge transport pathways, and strong structural integrity. Although the OER stability of the catalyst, consistent with other metal (hydr)oxide/carbon composites, is a critical concern, largely because the carbon support is intrinsically unstable under OER conditions, this hierarchical compound design presents a promising strategy for advancing OER catalysis using first-row transition metals.