Mariandry, KevinKokate, RavindraSomerville, Samuel V.Gloag, LucyCheong, SoshanCarroll, Liam R.Kumar, Priyank V.Gooding, J. JustinTilley, Richard D.2025-05-302025-05-300897-4756WOS:001140770000001ORCID:/0000-0001-7548-1521/work/172016334https://www.webofscience.com/api/gateway?GWVersion=2&SrcApp=anu_research_portal_plus2&SrcAuth=WosAPI&KeyUT=WOS:001140770000001&DestLinkType=FullRecord&DestApp=WOS_CPLhttps://hdl.handle.net/1885/733755260Growing Pt on Ag nanoparticles is a promising approach to forming catalysts that present active sites with both Pt and Ag available to improve the activity for the hydrogen evolution reaction (HER). By carefully controlling the concentration of a Pt precursor, the amount of Pt-decorated particles onto the Ag nanoparticles could be controlled to grow Pt islands between 0.6 and 1.5 nm. As a result, the relative amounts of the Ag-Pt active sites could be tuned. The smallest, 0.6 nm Pt islands on the Ag nanoparticle, with the highest ratio of Ag-Pt to Pt-Pt sites was found to have the highest activity and an accelerated Volmer step. DFT modeling showed that the improved performance was due to increased electron density on Pt from electron donation from neighboring Ag that leads to weaker Pt-H binding and the presence of more oxophilic Ag that can bind -OH on the active site that accelerates the water splitting.We acknowledge support from Microscopy Australia and the Mark Wainwright Analytical Centre and Electron Microscope Unit at the University of New South Wales. We acknowledge the Solid State and Elemental Analysis Unit (SSEAU) within the Mark Wainwright Analytical Centre (MWAC) at UNSW Sydney for access to XPS facilities. S.V.S. acknowledges support from the Australian Government Research Training Program (RTP) scholarship. This work was supported by the Australian Research Council Discovery Project DP190102659, DP200100143, and DP230100596 (to R.D.T.); Australian Research Council Discovery Project DP210102698 (to J.J.G.); and Australian Research Council LIEF grant LE200100033 (to R.D.T.). This work was supported by the Australian Research Council Discovery Project DP190102659, DP200100143, and DP230100596 (to R.D.T.); Australian Research Council Discovery Project DP210102698 (to J.J.G.); and Australian Research Council LIEF grant LE200100033 (to R.D.T.). We acknowledge support from Microscopy Australia and the Mark Wainwright Analytical Centre and Electron Microscope Unit at the University of New South Wales. We acknowledge the Solid State and Elemental Analysis Unit (SSEAU) within the Mark Wainwright Analytical Centre (MWAC) at UNSW Sydney for access to XPS facilities. S.V.S. acknowledges support from the Australian Government Research Training Program (RTP) scholarship.9enPublisher Copyright: © 2023 American Chemical Society.Enhanced electrocatalytic activityOne-pot synthesisTransition-metalsHigh-performanceNanocrystalsCatalystsShrinkingGrowthAcid202310.1021/acs.chemmater.3c0176585177064510