The TNiFe-P@NC presented excellent HER performance with an overpotential of 40 mV at 10 mA cm ⁻² and excellent stability in KOH solution. An assembled NiFe-P@NC||NiFe-P@NC electrolyzer could drive 100/500 mA cm ⁻² in alkaline seawater electrolyte at 1.77/1.93 V.

Ultrafast quasi-solid microwave (60 s) is employed to achieve phosphorus-doped black TiO₂ supported Ru and Pt (Ru–Pt/P–TiO_2−x) for the HER with an overpotential of 14 mV at 10 mA cm⁻² in an acidic electrolyte.