Ni-doped carbon nanotubes fabricated by pulsed laser ablation in liquid as efficient electrocatalysts for oxygen evolution reaction

Transition–metal-doped carbon-based electrocatalysts have attracted attention as alternatives to noble metal electrocatalysts (e.g. IrO₂ and RuO₂) for oxygen evolution reaction (OER) because they are inexpensive and highly efficient. However, their poor catalytic activity and time-consuming synthesis remain a challenge. Herein, we report a facile and green technique using pulsed laser ablation for preparing Ni-doped multi-walled carbon nanotubes (Ni-MWCNTs) as OER catalysts. Ni-MWCNTs exhibit high surface area, oxygen-rich functional groups (e.g., hydroxyl and carboxyl), and successful doping of Ni in the carbon framework. The as-prepared Ni-MWCNTs exhibited excellent OER catalytic performance, with an overpotential of 320 mV at the current density of 10 mA cm⁻² in an alkaline medium, which is lower than that of the commercial RuO₂ catalyst. Furthermore, Ni-MWCNTs displayed the initial electrocatalytic activity after 10-h stability tests, demonstrating good electrochemical durability. We believe that this work provides a simple protocol for fabricating heteroatom-doped carbon nanotubes as high-performance OER electrocatalysts.