Magnesium ferrite nanostructures for detection of ethanol vapours - a first-principles study

Abstract

The adsorption behaviour and electronic properties of ethanol vapour on MgFe 2 O 4 ceramic nanostructures are studied using density functional theory technique. The structural stability of MgFe 2 O 4 nanostructure is determined with the help of formation energy. The adsorption behaviour of ethanol molecules on MgFe 2 O 4 base material is analysed in terms of average energy gap variation, Mulliken charge transfer, band gap and adsorption energy. The most prominent adsorption sites of ethanol vapours on MgFe 2 O 4 nanostructure are investigated at atomistic level. The density of states spectrum reveals the clear picture about the electronic properties of MgFe 2 O 4 nanostructure. The density of states and electronic band gap confirmed the adsorption of ethanol vapours on MgFe 2 O 4 nanostructure. The changes in the energy band gap and density of states are observed upon adsorption of ethanol vapour molecules on MgFe 2 O 4 nanostructure. The density of states spectrum also confirms the changes in peak maxima due to the transfer of electrons between MgFe 2 O 4 nanostructure and ethanol vapours. The adsorption of oxygen atom from ethanol vapour on iron in MgFe 2 O 4 is found to be more prominent rather than other adsorption sites. The findings show that MgFe 2 O 4 nanostructure can be utilized to sense the presence of ethanol vapour in the atmosphere.

A creative method to tune Fe–O interaction in ferrites

“…As the reduced forms of materials get oxidized with purified air at 250 ℃, the electrical conductivity is reduced due to trapping quasi-free electrons by oxygen chemisorption, the behavior of which is consistent with what we expect from an n-type semiconductor [39,49] from point A to point B (Fig. 7) fits simple exponential first-order reaction with respect to the change of the charge density with a rate constant of 1.867(7)×10 −5 s −1 due to oxygen chemisorption.…”