Galvani substitution modulated self-assembly of Cu@Pt nanowires with hierarchical microstructure for highly active hydrogen evolution

Abstract

Felicitously incorporating noble metals with some transition metals to fabricate composite nanoagents with diverse shape and microarchitecture is a more promising solution for obtaining highly effective and cost-cutting catalyst. Herein, we report a facile and flexible synthesizing tactics, or Galvani substitution modulated self-assembly protocol, to fabricate Cu nanowire (core)-Pt nanoparticle (shell) unique microarchitecture (Cu-NWs@Pt) with porously hiberarchy. The comprehensive characterizations reveal that as-fabricated bimetallic nanowires with average aspect ratio of ca. 80 and apparent diameter of ca 60 nm, hold the razor-thin Cu–Pt alloy sublayer in the metallic contact interface, with the prebuilt Cu nanowires cladded by orderly oriented Pt nanograins to form loose, porous and stratiform structure. The thickness and microarchitecture of the Pt shell could be duly regulated by adjusting dosage of the metal precursors and substituting time. The verified formation of electronic synergic effect in the bimetallic nanoagents avails the adsorption of H to form metal-H species, leading to enhance the catalytic activity. Their catalytic ability overall increases with rising of Pt/Cu molar ratios, of which the Cu0.6Pt0.4 even exceeds Pt-NPs, with a turnover frequency of 77.26·min−1 and apparent activation energy of 30.25 kJ·mol−1, and maintaining 89% of the incipient catalytic ability after 5 recycling runs.