Shape-controlled platinum nanocrystals on boron-doped diamond

Platinum nanocrystals with different shapes are generally produced by wet-chemical synthesis in colloidal solutions. In this study, we shaped electrochemically Pt nanocrystals on highly boron doped diamond electrodes without adding surfactants or additives. Their shapes were controlled by varying deposition potential during electrodeposition process, as confirmed with high resolution scanning electron microscope. Their crystallography of Pt nanocrystals was analyzed through hydrogen adsorption/desorption behavior in acidic solutions. Oxygen reduction reactions on these nanocrystals were investigated, indicating shape dependence. The discussion on shaping mechanism reveals that hydrogen evolution reaction is deemed to be responsible.