| Full text | |
| Author(s): Show less - |
Amaral, D. C.
;
Rocha, L. S. R.
;
Granone, L. I.
;
Lage, M. M.
;
Churio, M. S.
;
Sanchez, M. D.
;
Longo, E.
;
Nascimento, H. M. S.
;
Assis, M.
;
Moura, F.
;
Ponce, M. A.
Total Authors: 11
|
| Document type: | Journal article |
| Source: | Inorganic Chemistry; v. 62, n. 31, p. 11-pg., 2023-07-21. |
| Abstract | |
Theinfluence of manganese modification on the spectroscopic featuresof manganese-doped CeO2 systems synthesized by the microwave-assistedhydrothermal route and their correlation with the presence of O defectivestructures were verified, focusing on their interaction with poisonousatmospheres. Raman and electron paramagnetic resonance studies confirmedthe presence of defective clusters formed by dipoles and/or quadrupoles.The number of paramagnetic species was found to be inversely proportionalto the doping concentration, resulting in an increase in the Mn2+ signal, likely due to the reduction of Mn3+ speciesafter the interaction with CO. X-ray photoelectron spectroscopy datashowed the pure system with 33% of its cerium species in the Ce3+ configuration, with an abrupt decrease to 19%, after thefirst modification with Mn, suggesting that 14% of the Ce3+ species are donating one electron to the Mn2+ ions, thusbecoming nonparamagnetic Ce4+ species. On the contrary,58% of the manganese species remain in the Mn2+ configurationwith five unpaired electrons, corroborating the paramagnetic featureof the samples seen in the electron paramagnetic resonance study. The impact of manganese modificationon the spectroscopicfeatures of microwave-assisted hydrothermally synthesized manganese-dopedCeO(2) systems was studied. Raman and electron paramagneticresonance confirmed defective cluster formation with dipoles and/orquadrupoles. A higher level of doping led to fewer paramagnetic speciesand an increased Mn2+ signal due to Mn3+ reductionupon CO interaction. X-ray photoelectron spectroscopy revealed a Ce3+ level of 33% in the pure system, which decreased to 19%after the first Mn modification, suggesting the donation of an electronto Mn2+ ions forming nonparamagnetic Ce4+ species;58% of Mn species remained as Mn2+, confirming the paramagneticnature seen in electron paramagnetic resonance studies. (AU) | |
| 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: | 18/20590-0 - Novel renewable rare-earth based hybrid nanomaterials for environmental sensing and energy-related applications |
| Grantee: | Leandro Silva Rosa Rocha |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 20/02352-5 - In-depth spectroscopic investigations of hybrid cerium oxide quantum-dots towards mitigation of the COVID-19 pandemic |
| Grantee: | Leandro Silva Rosa Rocha |
| Support Opportunities: | Scholarships abroad - Research Internship - Post-doctor |