Selective Synthesis of alpha-, beta-, and gamma-Ag2WO4 Polymorphs: Promising Platforms for Photocatalytic and Antibacterial Materials

Author(s)

Alvarez-Roca, Roman ^[1] ; Gouveia, Amanda Fernandes ^{[2, 3]} ; de Foggi, Camila Cristina ^[1] ; Lemos, Pablo Santana ^[1] ; Gracia, Lourdes ^[3] ; da Silva, Luis Fernando ^[4] ; Vergani, Carlos Eduardo ^[5] ; San-Miguel, Miguel ^[2] ; Longo, Elson ^{[2, 1]} ; Andres, Juan ^[3]

Affiliation

^[1] Univ Fed Sao Carlos, CDMF, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil

^[3] Jaume I Univ, Dept Phys & Analyt Chem, Castellon de La Plana 12071 - Spain

^[4] Univ Fed Sao Carlos, Phys Dept, BR-13565905 Sao Carlos, SP - Brazil

^[5] Sao Paulo State Univ Unesp, BR-14801903 Araraquara, SP - Brazil

• Document type: Journal article
• Source: Inorganic Chemistry; v. 60, n. 2, p. 1063-1080, JAN 18 2021.
• Web of Science Citations: 0

Abstract

Silver tungstate (Ag2WO4) shows structural polymorphism with different crystalline phases, namely, orthorhombic, hexagonal, and cubic structures that are commonly known as alpha, beta, and gamma, respectively. In this work, these Ag2WO4 polymorphs were selectively and successfully synthesized through a simple precipitation route at ambient temperature. The polymorph-controlled synthesis was conducted by means of the volumetric ratios of the silver nitrate/tungstate sodium dehydrate precursors in solution. The structural and electronic properties of the as-synthesized Ag2WO4 polymorphs were investigated by using a combination of Xray diffraction and Rietveld refinements, X-ray absorption spectroscopy, X-ray absorption near-edge structure spectroscopy, field-emission scanning electron microscopy images, and photoluminescence. To complement and rationalize the experimental results, first-principles calculations, at the density functional theory level, were carried out, leading to an unprecedented glimpse into the atomic-level properties of the morphology and the exposed surfaces of Ag2WO4 polymorphs. Following the analysis of the local coordination of Ag and W cations (clusters) at each exposed surface of the three polymorphs, the structure-property relationship between the morphology and the photocatalytic and antibacterial activities against amiloride degradation under ultraviolet light irradiation and methicillin-resistant Staphylococcus aureus, respectively, was investigated. A possible mechanism of the photocatalytic and antibacterial activity as well the formation process and growth of the polymorphs is also explored and proposed. (AU)

• FAPESP's process: 17/19548-7 - CDMF - Center for the Development of Functional Materials
• Grantee: Román Alvarez Roca
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 19/13507-2 - Characterization and antimicrobial activity of Ag2WO4 film deposited by femtosecond laser on titanium surface
• Grantee: Camila Cristina de Foggi
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 19/01732-1 - Photocatalytic activity of multifunctional semiconductors: influence of morphology and electron injection
• Grantee: Amanda Fernandes Gouveia
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• FAPESP's process: 13/07296-2 - CDMF - Center for the Development of Functional Materials
• Grantee: Elson Longo da Silva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 16/23891-6 - Computer modeling of condensed matter
• Grantee: Alex Antonelli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/12594-3 - CDMF - Center for the Development of Functional Materials
• Grantee: Camila Cristina de Foggi
• Support Opportunities: Scholarships in Brazil - Post-Doctorate