Effect of the Cross-Section Morphology in the Antimicrobial Properties of α-Ag<sub>2</sub>WO<sub>4</sub> Rods: An Experimental and Theoretical Study
Nivaldo F. Andrade Neto,
Marisa C. Oliveira,
José Heriberto O. Nascimento,
Elson Longo,
Renan A. P. Ribeiro,
Mauricio R. D. Bomio,
Fabiana V. Motta
Affiliations
Nivaldo F. Andrade Neto
Laboratory of Chemical Synthesis of Materials, Department of Materials Engineering, Federal University of Rio Grande do Norte—UFRN, Natal P.O. Box 1524, RN, Brazil
Marisa C. Oliveira
Department of Chemistry, Functional Materials Development Center, Federal University of São Carlos-UFSCar, São Carlos P.O. Box 676, SP, Brazil
José Heriberto O. Nascimento
Laboratory of Textile Chemical Process, Department of Textile Engineering, Federal University of Rio Grande do Norte—UFRN, Natal P.O. Box 1524, RN, Brazil
Elson Longo
Department of Chemistry, Functional Materials Development Center, Federal University of São Carlos-UFSCar, São Carlos P.O. Box 676, SP, Brazil
Renan A. P. Ribeiro
Laboratory of Theoretical Chemistry and Computational Modeling, Department of Natural and Earth Sciences, Minas Gerais State University—UEMG, Av. Paraná, 3001, Divinópolis 35501-170, MG, Brazil
Mauricio R. D. Bomio
Laboratory of Chemical Synthesis of Materials, Department of Materials Engineering, Federal University of Rio Grande do Norte—UFRN, Natal P.O. Box 1524, RN, Brazil
Fabiana V. Motta
Laboratory of Chemical Synthesis of Materials, Department of Materials Engineering, Federal University of Rio Grande do Norte—UFRN, Natal P.O. Box 1524, RN, Brazil
In this work, α-Ag2WO4 particles with different cross-sections were obtained using the co-precipitation method at different synthesis temperatures. The samples were characterized by X-ray diffraction (XRD), field-scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The antimicrobial activity was analyzed using the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) methods against the Escherichia coli and Salmonella spp. gram-negative bacteria. The antimicrobial tests against Escherichia coli and Salmonella spp. indicated that concentrations of 2.5–5 mg/mL and 5 mg/mL completely inhibit its growth, respectively. The antimicrobial activity was analyzed employing band-edge positions for ROS generations and the superficial distribution of Ag+ species that contribute to antimicrobial activity. Quantum-chemical calculations were used at the DFT level to investigate the surface-dependent reactivity of α-Ag2WO4, and we demonstrated how the antimicrobial properties could be tailored by the geometry and electronic structure of the exposed surfaces, providing guidelines for the morphology design.
