Designed Synthesis of Size‐Controlled PtCu Alloy Nanoparticles Encapsulated in Carbon Nanofibers and Their High Efficient Electrocatalytic Activity Toward Hydrogen Evolution Reaction

Well‐dispersed PtCu alloy nanoparticles (NPs) with a diameter of only ≈2 nm encapsulated in carbon nanofibers (CNFs) are synthesized using electrospinning technology followed by a graphitization process in a chemical vapor deposition furnace. Distinctly, even with a small amount of Pt, the PtCu/CNFs‐1:2 catalyst possesses outstanding hydrogen evolution reaction (HER) activity, including small overpotential, long‐term stability, and a high exchange current density as well as large double layer capacitance ( C dl ). The excellent HER performance of the PtCu/CNFs‐1:2 catalyst is attributed to the synergistic interaction between Pt and Cu, the uniform distribution of the alloy NPs and the use of CNFs with 3D architectures. This development may provide a simple, efficient, and green synthesis method to design bi‐ or multimetal alloys for use as the cathode electrocatalysts for the HER or other electrocatalytic devices.