Controlled Growth of Single‐Crystal Pd Quantum Dots on 2D Carbon for Large Current Density Hydrogen Evolution

Abstract The key issue for industrial large‐scale hydrogen production by water electrolysis is developing environment‐friendly electrocatalysts that can work well at large current densities and low overpotentials. Thanks to the superior advantages of 2D graphdiyne (GDY) on chemical structure and the alkyne bond strong reductivity, the highly selective, in situ growth of the single‐crystal Pd (111) quantum dots is achieved. The metal dots distribute uniformly and densely on the GDY surface (GDY‐Pd1) in a controllable way at low temperatures without adding additional reductive agents. Experimental and theoretical results show that the 2D GDY affords an ideal platform to construct highly selective and active electrocatalysts with accurate structures, defined valence states, facilitated charge transfer ability, and enhanced electric conductivity for hydrogen evolution reaction. Remarkably, the electrocatalyst can reach 500 and 1000 mA cm −2 at small overpotentials of only 201 and 261 mV, with high long‐term stability, which are better than most of the reported ones. The results demonstrate that 2D DGY is an excellent support in the controllable synthesis of metal quantum dots with well‐defined surface and structure and the potential to achieve large‐scale preparation. This study takes a critical step toward industrial hydrogen production.