Electrochemical Performance of Atmospheric Plasma‐Sprayed Raney Ni Electrodes for Hydrogen Evolution Reaction

Abstract This work reports a scalable fabrication of Raney Ni‐coated nickel mesh electrodes via atmospheric plasma spraying (APS), providing a cost‐effective alternative to vacuum‐based methods. By tailoring mesh specifications (0.18, 0.193, and 0.25 mm), the interplay between microstructure and hydrogen evolution reaction (HER) performance was systematically investigated. Post‐spray activation selectively removed Al‐rich phases (Ni 2 Al 3 , and NiAl 3 ), enlarging the electrochemical surface area. The 0.18 mm mesh exhibited the best activity in 1 M KOH at 70 °C, delivering 55 mV overpotential at −50 mA cm −2 with a Tafel slope of 49.1 mV dec −1 . Temperature–dependent studies confirmed accelerated kinetics through reduced charge transfer resistance. These findings highlight APS as a viable route for industrial‐scale production of durable, high‐performance alkaline electrolyzers.