Applications of Semiconducting Metal Oxides Gas Sensors

Abstract

Since the discovery of gas sensing properties of metal oxides in the 1960s, semiconducting metal oxides (SMO)-based gas sensors have attracted great attention for its advantages such as fast and sensitive detection portability and low cost, compared to other conventional techniques. This chapter extensively reviews the recent development of the SMO gas sensors for volatile organic compounds (VOCs) gases including ethanol, acetone, formaldehyde and BTX (benzene, toluene, xylene); environmental gases including CO2, O2, SO2, O3 and NH3; highly toxic gases including CO, H2S and NO2; and combustible gases including CH4, H2 and liquefied petroleum gas (LPG). The gas sensing properties of different metal oxides with diverse structures toward specific target gases have been individually discussed. Promising metal oxide materials for sensitive and selective detection of each gas have been identified. Moreover, design strategies, sensing mechanisms and related applications of SMO materials are also discussed in detail. This chapter gives classification of metal oxides sensors by analyte gas, providing a guideline for targeted design of SMO sensors.