Role of Surfaces in the Magnetic and Ozone Gas-Sensing Properties of ZnFe2O4 Nanoparticles: Theoretical and Experimental Insights
Year: 2021
Type: article
Abstract: The magnetic properties and ozone (O 3 ) gas-sensing activity of zinc ferrite (ZnFe 2 O 4 ) nanoparticles (NPs) were discussed by the combination of the results acquired by experimental procedures and density functional theory simulations. The ZnFe 2 O 4 NPs were synthesized via the microwave-assisted hydrothermal method by varying the reaction time in order to obtain ZnFe 2 O 4 NPs with different exposed surfaces and evaluate the influence on its properties. Regardless of the reaction time employed in the synthesis, the zero-field-cooled and field-cooled magnetization measurements showed superparamagnetic ZnFe 2 O 4 NPs with an average blocking temperature of 12 K. The (100), (110), (111), and (311) surfaces were computationally modeled, displaying the different undercoordinated surfaces. The good sensing activity of ZnFe 2 O 4 NPs was discussed in relation to the presence of the (110) surface, which exhibited low (−0.69 eV) adsorption enthalpy, promoting reversibility and preventing the saturation of the sensor surface. Finally, the O 3 gas-sensing mechanism could be explained based on the conduction changes of the ZnFe 2 O 4 surface and the increase in the height of the electron-depletion layer upon exposure toward the target gas. The results obtained allowed us to propose a mechanism for understanding the relationship between the morphological changes and the magnetic and O 3 gas-sensing properties of ZnFe 2 O 4 NPs.
Authors: Regiane Cristina de Oliveira, Renan Augusto Pontes Ribeiro, Guilherme Henrique Cruvinel, Rafael Aparecido Ciola Amoresi, Maria Helena Carvalho, Adilson Jesus Aparecido de Oliveira, Marisa Carvalho de Oliveira, Sergio Ricardo de Lazaro, Luís Fernando da Silva, Ariadne Cristina Catto, Alexandre Zirpoli Simões, Julio Ricardo Sambrano, Elson Longo
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3122844856