A simple electrochemical method for conversion of Pt wires to Pt concave icosahedra and nanocubes on carbon paper for electrocatalytic hydrogen evolution

Abstract

In the controlled synthesis of noble metal nanostructures using wet-chemical methods, normally, metal salts/complexes are used as precursors, and surfactants/ ligands are used to tune/stabilize the morphology of nanostructures. Here, we develop a facile electrochemical method to directly convert Pt wires to Pt concave icosahedra and nanocubes on carbon paper through the linear sweep voltammetry in a classic three-electrode electrochemical cell. The Pt wire, carbon paper and Ag/AgCl (3 mol L−1 KCl) are used as the counter, working and reference electrodes, respectively. Impressively, the formed Pt nanostructures exhibit better electrocatalytic activity towards the hydrogen evolution compared to the commercial Pt/C catalyst. This work provides a simple and effective way for direct conversion of Pt wires into well-defined Pt nanocrystals with clean surface. We believe it can also be used for preparation of other metal nanocrystals, such as Au and Pd, from their bulk materials, which could exhibit various promising applications.