Formation of Ag Nanoparticles on beta-Ag2WO4 through Electron Beam Irradiation: A Synergetic Computational and Experimental Study

Autor(es)

Roca, Roman A. ; Gouveia, Amanda F. ; Lemos, Pablo S. ; Gracia, Lourdes ; Andres, Juan ; Longo, Elson

• Tipo de documento: Artigo Científico
• Fonte: Inorganic Chemistry; v. 55, n. 17, p. 8661-8671, SEP 5 2016.
• Citações Web of Science: 17

Resumo

In the present work, a combined theoretical and experimental study was performed on the structure, optical properties, and growth of Ag nanoparticles in metastable beta-Ag2WO4 microcrystals. This material was synthesized using the precipitation method without the presence of surfactants. The structural behavior was analyzed using X-ray diffraction and Raman and infrared spectroscopy. Field-emission scanning electron microscopy revealed the presence of irregular spherical-like Ag nanoparticles on the beta-Ag2WO4 micro-crystals, which were induced by electron beam irradiation under high vacuum conditions. A detailed analysis of the optimized beta-Ag2WO4 geometry and theoretical results enabled interpretation of both the Raman and infrared spectra and provided deeper insight into rationalizing the observed morphology. In addition, first-principles calculations, within the quantum theory of atoms in molecules framework, provided an in-depth understanding of the nucleation and early evolution of Ag nanoparticles. The Ag nucleation and formation is the result of structural and electronic changes of the {[}AgO6] and {[}AgO5] clusters as a constituent building block of beta-Ag2WO4, which is consistent with Ag metallic formation. (AU)

• Processo FAPESP: 13/07296-2 - CDMF - Centro de Desenvolvimento de Materiais Funcionais
• Beneficiário: Elson Longo da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 13/26671-9 - Estudo teórico-experimental de semicondutores multifuncionais
• Beneficiário: Amanda Fernandes Gouveia
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 12/14004-5 - Investigação das propriedades fotoluminescentes e fotocatalíticas de pós de BaWO4 e BaMoO4 puros e dopados com Mn, Cu e Zn
• Beneficiário: Júlio César Sczancoski
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado