Kang, Yun Sik Jung, Jae Young Choi, Daeil Sohn, Yeonsun Lee, Soo-Hyoung Lee, Kug-Seung Kim, Nam Dong Kim, Pil Yoo, Sung Jong 2024-01-19T17:34:34Z 2024-01-19T17:34:34Z 2021-09-04 2020-04-08 1944-8244 https://pubs.kist.re.kr/handle/201004/118736 Galvanic displacement reaction has been considered a simple method for fabricating hollow nanoparticles. However, the formation of hollow interiors in nanoparticles is not easily achieved owing to the easy oxidization of transition metals, which results in mixed morphologies, and the presence of surfactants on the nanoparticle surface, which severely deteriorates the catalytic activity. In this study, we developed a facile gram-scale methodology for the one-pot preparation of carbon-supported PtNi hollow nanoparticles as an efficient and durable oxygen reduction electrocatalyst without using stabilizing agents or additional processes. The hollow structures were evolved from sacrificial Ni nanoparticles via an in situ galvanic displacement reaction with a Pt precursor, directly following a preannealing process. By sampling the PtNi/C hollow nanoparticles at various reaction times, the structural formation mechanism was investigated using transmission electron microscopy with energy-dispersive X-ray spectroscopy mapping/line-scan profiling. We found out that the structure and morphology of the PtNi hollow nanoparticles were controlled by the acidity of the metal precursor solution and the nanoparticle core size. The synthesized PtNi hollow nanoparticles acted as an oxygen reduction electrocatalyst, with a catalytic activity superior to that of a commercial Pt catalyst. Even after 10 000 cycles of harsh accelerated durability testing, the PtNi/C hollow electrocatalyst showed high performance and durability. We concluded that the Pt-rich layers on the PtNi hollow nanoparticles improved the catalytic activity and durability considerably English American Chemical Society REDUCTION REACTION REPLACEMENT REACTION NANOSTRUCTURES PLATINUM NANOCRYSTALS PERFORMANCE NANOFRAMES MONOLAYER CATALYSIS SHELL Formation Mechanism and Gram-Scale Production of PtNi Hollow Nanoparticles for Oxygen Electrocatalysis through In Situ Galvanic Displacement Reaction Article 10.1021/acsami.9b22615 1 ACS Applied Materials & Interfaces, v.12, no.14, pp.16286 - 16297 ACS Applied Materials & Interfaces 12 14 16286 16297 scie scopus 000526583500031 2-s2.0-85083080374 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Science & Technology - Other Topics Materials Science Article REDUCTION REACTION REPLACEMENT REACTION NANOSTRUCTURES PLATINUM NANOCRYSTALS PERFORMANCE NANOFRAMES MONOLAYER CATALYSIS SHELL hollow nanoparticle gram-scale production nanoscale Kirkendall effect galvanic displacement reaction oxygen reduction reaction