Surface-Oxidized Dicobalt Phosphide Nanoneedles as a Nonprecious, Durable, and Efficient OER Catalyst

Needle-shaped narrow hexagonal phase 1D nanostructures of dicobalt phosphide (Co2P) are reported as efficient electrocatalysts for the oxygen evolution reaction (OER). Without other metal incorporation, which was typically followed for enhancing the OER activity, the electrochemical performance was observed to be superior in comparison to all reported cobalt-based nanostructured metal phosphides. For anodic metamorphosis, these nanostructures, like all other metal phosphides, undergo surface oxidation but remain more active and superior to pure cobalt oxides as well as surface-oxidized different shaped monocobalt phosphides. Moreover, the synthesis was also followed by adopting a moderate synthetic protocol where PH3 gas was used as a phosphorus source and also scaled up to the gram level. In addition, the hydrogen evolution reaction (HER) performance of these phosphides was further studied, and the performance was observed to be comparable to that in the best reports.