Ultrasmall (<2 nm) Au@Pt Nanostructures: Tuning the Surface Electronic States for Electrocatalysis

Autor(es)

Germano, Lucas D. ^[1] ; Marangoni, Valeria S. ^[1] ; Mogili, Naga V. V. ^[2] ; Seixas, Leandro ^[1] ; Maroneze, Camila M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Prebiteriana Mackenzie, MackGraphe Graphene & Nanomat Res Ctr, Rua Consolacao 896, BR-01302907 Sao Paulo, SP - Brazil

^[2] LNNano, CNPEM, BR-13083970 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACS APPLIED MATERIALS & INTERFACES; v. 11, n. 6, p. 5661-5667, FEB 13 2019.
• Citações Web of Science: 3

Resumo

The ability to tune the electronic properties of nanomaterials has played a major role in the development of sustainable energy technologies. Metallic nanocatalysts are at the forefront of these advances. Their unique properties become even more interesting when we can control the distribution of the electronic states in the nanostructure. Here, we provide a comprehensive evaluation of the electronic surface states in ultrasmall metallic nanostructures by combining experimental and theoretical methods. The developed strategy allows the controlled synthesis of bimetallic nanostructures in the core-shell configuration, dispensing of the use of any surfactant or stabilizing agents, which usually inactivate important surface phenomena. The synthesized ultrasmall Au@Pt nanoarchitecture (similar to 1.8 nm) presents an enhanced performance catalyzing the hydrogen evolution reaction. First-principles calculations of projected and space-resolved local density of states of Au-55@Pt-92 (core-shell), Au55Pt92 (alloy), and Pt-147 nanoparticles show a prominent increase in the surface electronic states for the core-shell bimetallic nanomaterial. It arises from a more-effective charge transfer from gold to the surface platinum atoms in the core shell configuration. In pure Pt-147 or Au55Pt92 alloy nanoparticles, a great part of the electronic states near the Fermi level is buried in the core atoms, disabling these states for catalytic applications. The proposed experimental-theoretical approach may be useful for the design of other systems composed of metallic nanoparticles supported on distinct substrates, such as two-dimensional materials and porous matrices. These nanomaterials find several applications not only in heterogeneous catalysis but also in sensing and optoelectronic devices. (AU)

• Processo FAPESP: 16/20799-1 - Arquiteturas de heteroestruturas de van der Waals em meio líquido: aplicação em dispositivos fotônicos
• Beneficiário: Valeria Spolon Marangoni
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/00486-1 - Graphene 2017
• Beneficiário: Leandro Seixas Rocha
• Modalidade de apoio: Auxílio à Pesquisa - Reunião - Exterior
• Processo FAPESP: 12/50259-8 - Grafeno: fotônica e opto-eletrônica: colaboração UPM-NUS
• Beneficiário: Antonio Helio de Castro Neto
• Modalidade de apoio: Auxílio à Pesquisa - Programa SPEC