Plasma-engineered defect-nitrogen complexes for enhanced Pt-catalyzed hydrogen evolution

Anion exchange membrane (AEM) water electrolysis is emerging as a mainstream approach for water electrolysis. However, in alkaline electrolytes, the extremely low H+ concentration limits the hydrogen evolution reaction (HER) due to the sluggish kinetics of water dissociation. This work proposes a novel plasma strategy that results in negative sheath ion implantation and surface sputtering effects to fabricate abundant pores and crater nanostructures on the surface of a nickel foam (NF) support. Simultaneously, nitrogen ions are doped into the bottoms and sidewalls of the pores and craters. Furthermore, platinum (Pt) atoms are naturally embedded into these structures through plasma-induced room-temperature in-situ reduction of chloroplatinic acid molecules. Due to the interlocking mechanism of the pores and craters, combined with the anchoring effect of nitrogen ions, the ultrasmall Pt nanoparticles are uniformly dispersed within the pores and craters on the rough surface of NF. The resulting NF-VN-Pt catalytic electrode exhibits superior HER electrocatalytic performance in a 1 M KOH alkaline electrolyte, with HER overpotentials of 31 mV at 10 mA cm−2 and 197 mV at 1000 mA cm−2, outperforming the commercial Pt/C catalyst. The work provides a novel approach for preparing supported noble metal catalysts with broad applicability.