Promoting Alkaline Hydrogen Evolution Catalysis on P-Decorated, Ni-Segregated Pt–Ni–P Nanowires via a Synergetic Cascade Route

Abstract

Although both the water dissociation and intermediates’ (H* and OH–) adsorption/desorption are two critical steps for alkaline hydrogen evolution, very little effort has been expended to target the latter step to further boost the alkaline hydrogen evolution catalysis. To overcome this limitation, we designed phosphorus (P)-modified, nickel (Ni)-segregated platinum (Pt)–Ni nanowires as highly efficient electrocatalysts for alkaline hydrogen evolution. The segregated Ni can be evolved into Ni(OH)x as the active site for water splitting. Then, the modified P with high oxophilicity on the catalyst surface serves as a site to anchor OH–, largely preventing the competitive adsorption of OH– and H* on active Pt sites as well as promoting the adsorption and desorption rate of H*. Consequently, it achieves excellent activity and stability in 1 M KOH with a current density as high as 42.5 mA/cm2 (@–0.07 VRHE) and limited overpotential decay after 18 h long-term test, outperforming most reported alkaline hydrogen evolution reaction electrocatalysts.