Constructing Ni3Se2‐Nanoisland‐Confined Pt1Mo1 Dual‐Atom Catalyst for Efficient Hydrogen Evolution in Basic Media

Constructing efficient and stable catalysts is the key to achieving green hydrogen production through electrolysis of water. Atomically dispersed catalysts have received widespread attention due to their high atomic utilization and catalytic efficiency. Herein, Pt 1 Mo 1 dual‐atom catalysts anchored on the nickel selenide nanoisland (Pt 1 Mo 1 /Ni 3 Se 2 ) are prepared by a two‐step method. It only needs 53 mV to deliver the current density of 10 mA cm −2 in 1 M KOH media, and the mass activity at 200 mV is approximately 4.13 times higher than that of Pt/C. In addition, the Pt 1 Mo 1 /Ni 3 Se 2 also exhibits electrochemical stability of nearly 60 h at 20 mA cm −2 . It is shown in the studies that the synergistic effect between Pt and Mo atoms enables the migration of electrons around Mo atoms toward Pt, thus realizing charge redistribution. Further density functional theory calculations verify that synergistic effect of Pt and Mo atoms could optimize the adsorption of H*, enhancing the hydrogen evolution reaction activity. Moreover, the Ni 3 Se 2 nanoisland prevents the aggregation of Pt and Mo dual atom, effectively improving the stability of the catalyst. In this work, a nanoisland confined strategy is provided to construct atomically dispersed catalysts with high activity and stability for water splitting.