Development of cost-effective electrocatalysts toward the alkaline hydrogen evolution reaction (HER) is crucial for electrolytic hydrogen production applications. In this communication, we report the electrodeposition of cobalt–phosphorus nanoparticles on a polyimide derived N-doped carbon nanosheet array supported on carbon cloth (Co–P@NC/CC) and it is a robust 3D HER electrode. In 1.0 M KOH, this Co–P@NC/CC shows outstanding catalytic activity with the demand of a low overpotential of 75 mV to drive 10 mA cm−2, outperforming most reported Co–P catalysts. Notably, it also demonstrates strong long-term electrochemical durability.
