Anomalous Resistance of LBCO Gas Sensors Induced by Electro-Catalyzed Surface O-H Reactions

Abstract

Anomalous sensor behavior of a LBCO gas sensor in response to gas switching in O 2 /H 2 ambient is demonstrated. Developed from a LBCO thin film epitaxial-grown using pulsed laser deposition, the gas sensor was also comparatively tested under different switching conditions of O 2 /H 2 , O 2 /N 2 and O 2 /Ar. In addition, temperature dependence of sensor resistance was characterized in the gas mixture of 4% H 2 + 96% N 2 diluted with different levels of oxygen. The anomalous sensor behavior was ascribed to an electro-catalyzed H-O reaction in O 2 + H 2 mixture mediated by the LBCO film, and detailed discussion of the reaction mechanism was given for the first time. Proved to have extremely high sensitivity to H 2 , the LBCO sensor offers great potential in sensitive detection of H 2 as well as other reducing gases.