| Autor: |
Campos, Raquel Dantas, Menezes de Oliveira, André Luiz, Rostas, Arpad Mihai, Kuncser, Andrei Cristian, Negrila, Constatin Catalin, Galca, Aurelian-Catalin, Félix, Camila, Castellano, Lúcio, da Silva, Fausthon Fred, dos Santos, Iêda Maria Garcia |
| Předmět: |
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| Zdroj: |
New Journal of Chemistry; 2/7/2023, Vol. 47 Issue 5, p2177-2188, 12p |
| Abstrakt: |
Zeolitic imidazole frameworks (ZIFs) and TiO2 based composites have recently attracted interest to control pathogenic microorganism growth. In this context, two novel TiO2/ZIF-67 nanocomposites were synthesized by the microwave-assisted solvothermal method using two different routes: one pot composite (OPC) and two step composite (TSC) syntheses. X-ray powder diffraction and vibrational spectroscopy data revealed the formation of crystalline ZIF-67 and disordered TiO2 in the OPC composite, while both phases were crystalline in the TSC sample. Sphere-like morphologies were obtained for both materials, as indicated by SEM and TEM images. XPS measurements showed mixed-valence Ti (Ti3+/Ti4+) and Co (Co2+/Co3+) on the surface of both materials, while EPR analysis confirmed the presence of Co2+ ions and oxygen-related defects. The results showed that TiO2 has no antimicrobial activity against Staphylococcus aureus, while the TSC has higher and the OPC has lower activity than pure ZIF-67. Highly efficient biocidal activity at a concentration of 2.5 mg mL−1 was observed for the TSC. The difference in the antimicrobial performance of the nanocomposites can be correlated with the balance between structural order/disorder, which depends on the synthesis route used, and the material solubility. The results also indicate the release of Co ions and the ligand as a possible mechanism together with redox reactions to inactivate bacteria. Thus, this work provides simple and promising synthesis routes to obtain TiO2/ZIF-67 nanocomposites for potential use as new antimicrobial agents. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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