title: Microwave-assisted hydrothermal synthesis of Ag₂(W(1-x)Mox)O₄ heterostructures: Nucleation of Ag, morphology, and photoluminescence properties.
abstract: Ag2W(1-x)MoxO4 (x=0.0 and 0.50) powders were synthesized by the co-precipitation (drop-by-drop) method and processed using a microwave-assisted hydrothermal method. We report the real-time in situ formation and growth of Ag filaments on the Ag2W(1-x)MoxO4 crystals using an accelerated electron beam under high vacuum. Various techniques were used to evaluate the influence of the network-former substitution on the structural and optical properties, including photoluminescence (PL) emission, of these materials. X-ray diffraction results confirmed the phases obtained by the synthesis methods. Raman spectroscopy revealed significant changes in local order-disorder as a function of the network-former substitution. Field-emission scanning electron microscopy was used to determine the shape as well as dimensions of the Ag2W(1-x)MoxO4 heterostructures. The PL spectra showed that the PL-emission intensities of Ag2W(1-x)MoxO4 were greater than those of pure Ag2WO4, probably because of the increase of intermediary energy levels within the band gap of the Ag2W(1-x)MoxO4 heterostructures, as evidenced by the decrease in the band-gap values measured by ultraviolet-visible spectroscopy.
authors.affiliation: LIEC-Universidade Federal de São Carlos, Rod. Washington Luis, km 235, São Carlos, SP CEP: 13565-905, Brazil.
authors.forename: M D P
authors.initials: MD
authors.lastname: Silva
authors.affiliation: UNIFESP-Universidade Federal de São Paulo, Rua Prof. Artur Riedel, 275, Diadema, SP CEP 09972-270, Brazil. Electronic address: rosanaf.gon@gmail.com.
authors.forename: R F
authors.initials: RF
authors.lastname: Gonçalves
authors.affiliation: IFMA - Instituto Federal do Maranhão, Avenida Getúlio Vargas, no 04 - Monte Castelo, São Luís, MA CEP 65030-005, Brazil.
authors.forename: I C
authors.initials: IC
authors.lastname: Nogueira
authors.affiliation: USP - Universidade de São Paulo, Av. Trabalhador São-Carlense, 400 - Arnold Schimidt, São Carlos, SP CEP 13566-590, Brazil.
authors.forename: V M
authors.initials: VM
authors.lastname: Longo
authors.affiliation: LIEC-Universidade Federal de São Carlos, Rod. Washington Luis, km 235, São Carlos, SP CEP: 13565-905, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Mondoni
authors.affiliation: LIEC-Universidade Federal de São Carlos, Rod. Washington Luis, km 235, São Carlos, SP CEP: 13565-905, Brazil.
authors.forename: M G
authors.initials: MG
authors.lastname: Moron
authors.affiliation: UTFPR-Universidade Tecnológica Federal do Paraná, Av. Alberto Carazzai, 1640, Cornélio Procópio, PR CEP 86300-000, Brazil.
authors.forename: Y V
authors.initials: YV
authors.lastname: Santana
authors.affiliation: LIEC-IQ-Universidade Estadual Paulista, P.O. Box 355, Araraquara, SP CEP 14801-907, Brazil.
authors.forename: E
authors.initials: E
authors.lastname: Longo
keywords: Ag(2)MoO(4); Ag(2)WO(4); Morphology; Photoluminescence; Raman spectroscopy