Novel gas sensor with dual response under CO(g) exposure: Optical and electrical stimuli

Author(s)

Rocha, L. S. R. ^[1] ; Cilense, M. ^[2] ; Ponce, M. A. ^[3] ; Aldao, C. M. ^[3] ; Oliveira, L. L. ^[1] ; Longo, E. ^[2] ; Simoes, A. Z. ^[1]

Affiliation

^[1] Sao Paulo State Univ UNESP, Sch Engn, Ave Dr Ariberto Pereira da Cunha 333, BR-12516410 Sao Paulo - Brazil

^[2] Sao Paulo State Univ UNESP, Inst Chem, BR-14801907 Sao Paulo - Brazil

^[3] Inst Mat Sci & Technol Invest INTEMA, Juan B Justo 4302, RA-7600 Mar Del Plata, Buenos Aires - Argentina

• Document type: Journal article
• Source: PHYSICA B-CONDENSED MATTER; v. 536, p. 280-288, MAY 1 2018.
• Web of Science Citations: 2

Abstract

In this work, a lanthanum (La) doped ceria (CeO2) film, which depicted a dual gas sensing response (electric and optical) for CO(g) detection, was obtained by the microwave-assisted hydrothermal (HAM) synthesis and deposited by the screen-printing technique, in order to prevent deaths by intoxication with this life-threatening gas. An electric response under CO(g) exposure was obtained, along with an extremely fast optical response for a temperature of 380 degrees C, associated with Ce+4 reduction and vacancy generation. A direct optical gap was found to be around 2.31 eV from UV-Vis results, which corresponds to a transition from valence band to 4f states. Due to the anomalous electron configuration of cerium atoms with 4f electrons in its reduced state, they are likely to present an electric conduction based on the small polaron theory with a hopping mechanism responsible for its dual sensing response with a complete reversible behaviour. (C) 2017 Elsevier B.V. All rights reserved. (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