Photocatalytic ozone sensor based on mesoporous indium oxide: Influence of the relative humidity on the sensing performance

• Published in: Thin solid films Vol. 520; no. 3; pp. 918 - 921
• Main Authors: Wagner, Th, Hennemann, J., Kohl, C.-D., Tiemann, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 30.11.2011; Elsevier
• Subjects: Detection; Exact sciences and technology; General equipment and techniques; Humidity; Hydroxyl groups; Indium oxide; Indium oxides; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Nanostructure; Ozone; Photocatalytic ozone sensor; Physics; Relative humidity; Sensors; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Photocatalytic ozone sensor; Relative humidity; Indium oxide; Porous materials; Active site; Humidity; Hydroxyl group; Illumination; Gas sensors; Mesoporosity
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2011.04.181

Mesoporous In 2O 3, synthesized by a nanocasting procedure, is used as a resistive gas sensor for ozone in very low concentrations (from 20 ppb to 2.4 ppm) at room temperature. Its sensing performance is substantially increased by illumination with blue light (460 nm, 2.7 eV). For low ozone concentrations the sensor response increases with increasing humidity. However, higher humidity also results in the occurrence of a saturation of the response at lower ozone concentrations; this is rationalized by assuming a poisoning of surface active sites by hydroxyl groups.