Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data

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dc.contributor.authorSousa, Giancarlo da Silva
dc.contributor.authorNobre, Francisco Xavier
dc.contributor.authorAraújo Júnior, Edgar Alves
dc.contributor.authorSambrano, Julio Ricardo [UNESP]
dc.contributor.authorAlbuquerque, Anderson dos Reis
dc.contributor.authorBindá, Rosane dos Santos
dc.contributor.authorCouceiro, Paulo Rogério da Costa
dc.contributor.authorBrito, Walter Ricardo
dc.contributor.authorCavalcante, Laécio Santos
dc.contributor.authorSantos, Maria Rita de Morais Chaves
dc.contributor.authorde Matos, José Milton Elias
dc.contributor.institutionUniversidade Federal do Piauí
dc.contributor.institutionCiência e Tecnologia do Amazonas
dc.contributor.institutionUniversidade Federal do Amazonas
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.contributor.institutionUniversidade Federal do Rio Grande do Norte (UFRN)
dc.contributor.institutionUniversidade Estadual do Piauí
dc.contributor.institutionCentro Universitário Santo Agostinho – UNIFSA
dc.date.accessioned2018-12-11T17:37:53Z
dc.date.available2018-12-11T17:37:53Z
dc.date.issued2018-01-01
dc.description.abstractIn this paper, we report about hydrothermal synthesis, structural characterization and photocatalytic properties of beta-silver molybdate (β-Ag2MoO4) microcrystals obtained at different temperatures (100, 120, 140 and 160 °C) for 2 h. These crystals were characterized structurally using X-ray diffraction (XRD), X-ray fluorescence, Rietveld refinement, micro-Raman (m-Raman) and Fourier-transform infrared (FT-IR) spectroscopies. Experimental and theoretical band gap values were correlated by ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy and periodic first-principles calculations in the framework of density functional theory (DFT) with the B3LYP-D3 hybrid functional. The crystals morphology was observed through field-emission scanning electron microscopy (FE-SEM) images. The photocatalytic properties of these crystals were investigated for degradation of rhodamine B (RhB) dye under UV-light. XRD patterns and Rietveld refinement data indicate that all crystals exhibit a spinel-type cubic structure with space group (Fd3′m) formed by tetrahedral [MoO4] clusters and distorted octahedral [AgO6] clusters. m-Raman spectra exhibited five Raman-active modes in a range from 50 to 1000 cm−1, while FT-IR spectra have three infrared active modes in a range from 400 to 1100 cm−1. The experimental results from Raman and IR modes are in reasonable agreement with theoretically calculated results. Experimental UV–Vis spectra indicate a decrease in optical band gap (Egap = 3.35 eV to 3.32 eV) with the temperature rise. The calculated band structure revealed an indirect optical band gap (Egap) of approximately 3.94 eV. Moreover, theoretical calculations based on density of states and electron density maps were employed to understand the polarization phenomenon induced by structural defects in the β-Ag2MoO4 microcrystals. FE-SEM images revealed that the increase of processing temperatures promotes a change in shape of microcrystals from potatoes-like to coral-like. Finally, photocatalytic measures to degradation of the RhB dye resulted in the best catalytic performance for β-Ag2MoO4 microcrystals synthesized at temperatures of 120 and 140 °C, corresponding to 97.3% and 96.8% in the photodegradation of RhB dye under UV–light up to 2 h. The stability of the β-Ag2MoO4 was investigated by reusing, resulting in f 97.2, 93.9 and 78.8% degradation of the RhB dye for the first, second and third cycle, respectively.en
dc.description.affiliationLaboratório Interdisciplinar de Materiais Avançados LIMAV-UFPI Universidade Federal do Piauí, CEP 69049-550
dc.description.affiliationInstituto Federal de Educação Ciência e Tecnologia do Amazonas, Campus Coari, IFAM-CCO-AM, CEP 69460-000
dc.description.affiliationLaboratório de Físico-Química LFQ-UFAM Universidade Federal do Amazonas, CEP 69077-000
dc.description.affiliationGrupo de Modelagem e Simulação Molecular INCTMN-UNESP São Paulo State University, CEP 17033-360
dc.description.affiliationInstituto de Química Universidade Federal do Rio Grande do Norte (UFRN), atal-RN, CEP 59078-970
dc.description.affiliationPPGQ-CCN-GERATEC Universidade Estadual do Piauí, Rua: João Cabral, N. 2231, P.O. Box 381
dc.description.affiliationCentro Universitário Santo Agostinho – UNIFSA, Av. Valter alencar 665 – Bairro São Pedro, CEP 64019-625
dc.description.affiliationUnespGrupo de Modelagem e Simulação Molecular INCTMN-UNESP São Paulo State University, CEP 17033-360
dc.description.sponsorshipCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.description.sponsorshipConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.description.sponsorshipFundação de Amparo à Pesquisa do Estado do Piauí
dc.description.sponsorshipIdCNPq: 304261/2009-2
dc.description.sponsorshipIdCNPq: 304531/2013-8
dc.description.sponsorshipIdCNPq: 479644/2012-8
dc.identifierhttp://dx.doi.org/10.1016/j.arabjc.2018.07.011
dc.identifier.citationArabian Journal of Chemistry.
dc.identifier.doi10.1016/j.arabjc.2018.07.011
dc.identifier.issn1878-5352
dc.identifier.scopus2-s2.0-85050854719
dc.identifier.urihttp://hdl.handle.net/11449/180069
dc.language.isoeng
dc.relation.ispartofArabian Journal of Chemistry
dc.relation.ispartofsjr0,591
dc.rights.accessRightsAcesso restrito
dc.sourceScopus
dc.subjectBand gap
dc.subjectCoral-like
dc.subjectPhotocatalytic properties
dc.subjectTheoretical calculations
dc.subjectβ-Ag2MoO4 microcrystals
dc.titleHydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical dataen
dc.typeArtigo
unesp.departmentMatemática - FCpt

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