Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data
In 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 diffra...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020-01-01
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| Series: | Arabian Journal of Chemistry |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S187853521830159X |
| _version_ | 1818425069486997504 |
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| author | Giancarlo da Silva Sousa Francisco Xavier Nobre Edgar Alves Araújo Júnior Julio Ricardo Sambrano Anderson dos Reis Albuquerque Rosane dos Santos Bindá Paulo Rogério da Costa Couceiro Walter Ricardo Brito Laécio Santos Cavalcante Maria Rita de Morais Chaves Santos José Milton Elias de Matos |
| author_facet | Giancarlo da Silva Sousa Francisco Xavier Nobre Edgar Alves Araújo Júnior Julio Ricardo Sambrano Anderson dos Reis Albuquerque Rosane dos Santos Bindá Paulo Rogério da Costa Couceiro Walter Ricardo Brito Laécio Santos Cavalcante Maria Rita de Morais Chaves Santos José Milton Elias de Matos |
| author_sort | Giancarlo da Silva Sousa |
| collection | DOAJ |
| description | In 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. Keywords: β-Ag2MoO4 microcrystals, Theoretical calculations, Band gap, Coral-like, Photocatalytic properties |
| first_indexed | 2024-12-14T14:08:05Z |
| format | Article |
| id | doaj.art-6c6bc129d1f84510935a482c04215936 |
| institution | Directory Open Access Journal |
| issn | 1878-5352 |
| language | English |
| last_indexed | 2024-12-14T14:08:05Z |
| publishDate | 2020-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Arabian Journal of Chemistry |
| spelling | doaj.art-6c6bc129d1f84510935a482c042159362022-12-21T22:58:24ZengElsevierArabian Journal of Chemistry1878-53522020-01-0113128062825Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical dataGiancarlo da Silva Sousa0Francisco Xavier Nobre1Edgar Alves Araújo Júnior2Julio Ricardo Sambrano3Anderson dos Reis Albuquerque4Rosane dos Santos Bindá5Paulo Rogério da Costa Couceiro6Walter Ricardo Brito7Laécio Santos Cavalcante8Maria Rita de Morais Chaves Santos9José Milton Elias de Matos10Laboratório Interdisciplinar de Materiais Avançados, LIMAV-UFPI, Universidade Federal do Piauí, CEP 69049-550, Teresina, PI, Brazil; Centro Universitário Santo Agostinho – UNIFSA, Av. Valter alencar 665 – Bairro São Pedro, CEP 64019-625, Teresina, PI, BrazilInstituto Federal de Educação, Ciência e Tecnologia do Amazonas, Campus Coari, IFAM-CCO-AM, CEP 69460-000, AM, Brazil; Laboratório de Físico-Química, LFQ-UFAM, Universidade Federal do Amazonas, CEP 69077-000, Manaus, AM, BrazilLaboratório Interdisciplinar de Materiais Avançados, LIMAV-UFPI, Universidade Federal do Piauí, CEP 69049-550, Teresina, PI, BrazilGrupo de Modelagem e Simulação Molecular, INCTMN-UNESP, São Paulo State University, CEP 17033-360, Bauru, SP, BrazilInstituto de Química, Universidade Federal do Rio Grande do Norte (UFRN), Natal-RN, CEP 59078-970, BrazilLaboratório de Físico-Química, LFQ-UFAM, Universidade Federal do Amazonas, CEP 69077-000, Manaus, AM, BrazilLaboratório de Físico-Química, LFQ-UFAM, Universidade Federal do Amazonas, CEP 69077-000, Manaus, AM, BrazilLaboratório de Físico-Química, LFQ-UFAM, Universidade Federal do Amazonas, CEP 69077-000, Manaus, AM, BrazilPPGQ-CCN-GERATEC, Universidade Estadual do Piauí, Rua: João Cabral, N. 2231, P.O. Box 381, 64002-150 Teresina, PI, BrazilLaboratório Interdisciplinar de Materiais Avançados, LIMAV-UFPI, Universidade Federal do Piauí, CEP 69049-550, Teresina, PI, Brazil; Corresponding authors.Laboratório Interdisciplinar de Materiais Avançados, LIMAV-UFPI, Universidade Federal do Piauí, CEP 69049-550, Teresina, PI, Brazil; Corresponding authors.In 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. Keywords: β-Ag2MoO4 microcrystals, Theoretical calculations, Band gap, Coral-like, Photocatalytic propertieshttp://www.sciencedirect.com/science/article/pii/S187853521830159X |
| spellingShingle | Giancarlo da Silva Sousa Francisco Xavier Nobre Edgar Alves Araújo Júnior Julio Ricardo Sambrano Anderson dos Reis Albuquerque Rosane dos Santos Bindá Paulo Rogério da Costa Couceiro Walter Ricardo Brito Laécio Santos Cavalcante Maria Rita de Morais Chaves Santos José Milton Elias de Matos Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data Arabian Journal of Chemistry |
| title | Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data |
| title_full | Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data |
| title_fullStr | Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data |
| title_full_unstemmed | Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data |
| title_short | Hydrothermal synthesis, structural characterization and photocatalytic properties of β-Ag2MoO4 microcrystals: Correlation between experimental and theoretical data |
| title_sort | hydrothermal synthesis structural characterization and photocatalytic properties of β ag2moo4 microcrystals correlation between experimental and theoretical data |
| url | http://www.sciencedirect.com/science/article/pii/S187853521830159X |
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