Porous cobalt phosphide nanorod bundle arrays as hydrogen-evolving cathodes for electrochemical water splitting

• Porous CoP NBAs were prepared from the self-sacrificial Co3O4 NBAs precursor.
• CoP NBAs were explored as novel all-pH-efficient HER electrocatalysts.
• CoP NBAs showed excellent HER activity and good stability.

An advanced electrode composed of porous CoP nanorod bundle arrays (NBAs) on Ti plate was fabricated by using Co3O4 NBAs as precursors and developed as a robust self-supported hydrogen-evolving cathode for electrochemical water splitting. Such electrode exhibited remarkable activity for hydrogen evolution reaction in a wide pH range, affording a low onset overpotential, small Tafel slope, and long-term stability.