Nickel-Ion-Oriented Fabrication of Spiny PtCu Alloy Octahedral Nanoframes with Enhanced Electrocatalytic Performance

Metal cation is an emerging type of morphology controlling agency in nanoscience, but has rarely been used in fabrication of hollow structures. Herein, with the addition of Ni2+ ion, PtCu alloy octahedral nanoframes (PtCu AONFs) with plenty of spiny nanothorns on the apexes are synthesized via one-step hydrothermal reaction. Ni2+ ion plays a pivotal role in forming hollow structures because it facilitates the diffusion of Cu atoms in the replacement reaction between initially formed Cu templates and PtCl62–. The as-prepared PtCu AONFs show a superior electrocatalytical activity and durability toward oxygen reduction reaction (ORR) with a mass activity (MA) and specific activity (SA) of 0.28 A/mgPt and 0.50 mA/cm2 at 0.90 V vs reversible hydrogen electrode (RHE), which are 2.8- and 2.6-fold times that of commercial Pt/C (0.10 A/mgPt and 0.19 mA/cm2). In addition, the electrocatalytical oxidation property of PtCu AONFs toward methanol also better than that of commercial Pt/C. This study offers a new strategy for synthesizing hollow electrocatalysts with enhanced properties.