Shape-Controlled Synthesis of Concave Pt and Willow-Like Pt Nanocatalysts via Electrodeposition with Hydrogen Adsorption/Desorption and Investigation of Their Electrocatalytic Performances toward Ethanol Oxidation Reaction

Without introducing any surfactants and capping agents, concave Pt nanocubes, willow-like Pt nanocrystals, and spherical Pt nanoparticles were synthesized at different deposition potentials using a square-wave potential electrodeposition procedure. As the deposition potentials decreased from the double layer region to the hydrogen underpotential deposition region and finally into the hydrogen evolution reaction region under acidic conditions, the morphology of Pt nanocrystals changed from spherical Pt nanoparticles to willow-like Pt nanocrystals and finally to concave Pt nanocubes. We took advantage of the unique features of hydrogen adsorption/desorption on the surface of Pt in different potential regions to achieve the shape-controlled synthesis of Pt nanocrystals, and the different degrees of interaction between hydrogen and Pt played a key role in obtaining nanocrystals with various shapes. Concave Pt nanocubes exhibited excellent electrocatalytic activity to the ethanol oxidation reaction, as compared to commercial Pt/C catalysts. The peak current density in the positive scan of concave Pt nanocubes was 2.3 mA cm(-2), which was 4.7 times higher than that of commercial Pt/C.