Gas Sensing with Nanoporous In<sub>2</sub>O<sub>3</sub> under Cyclic Optical Activation: Machine Learning-Aided Classification of H<sub>2</sub> and H<sub>2</sub>O

Clean hydrogen is a key aspect of carbon neutrality, necessitating robust methods for monitoring hydrogen concentration in critical infrastructures like pipelines or power plants. While semiconducting metal oxides such as In<sub>2</sub>O<sub>3</sub> can monitor gas concentrat...

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Bibliographic Details
Main Authors: Dominik Baier, Alexander Krüger, Thorsten Wagner, Michael Tiemann, Christian Weinberger
Format: Article
Language:English
Published: MDPI AG 2024-09-01
Series:Chemosensors
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Online Access:https://www.mdpi.com/2227-9040/12/9/178
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Summary:Clean hydrogen is a key aspect of carbon neutrality, necessitating robust methods for monitoring hydrogen concentration in critical infrastructures like pipelines or power plants. While semiconducting metal oxides such as In<sub>2</sub>O<sub>3</sub> can monitor gas concentrations down to the ppm range, they often exhibit cross-sensitivity to other gases like H<sub>2</sub>O. In this study, we investigated whether cyclic optical illumination of a gas-sensitive In<sub>2</sub>O<sub>3</sub> layer creates identifiable changes in a gas sensor’s electronic resistance that can be linked to H<sub>2</sub> and H<sub>2</sub>O concentrations via machine learning. We exposed nanostructured In<sub>2</sub>O<sub>3</sub> with a large surface area of 95 m<sup>2</sup> g<sup>−1</sup> to H<sub>2</sub> concentrations (0–800 ppm) and relative humidity (0–70%) under cyclic activation utilizing blue light. The sensors were tested for 20 classes of gas combinations. A support vector machine achieved classification rates up to 92.0%, with reliable reproducibility (88.2 ± 2.7%) across five individual sensors using 10-fold cross-validation. Our findings suggest that cyclic optical activation can be used as a tool to classify H<sub>2</sub> and H<sub>2</sub>O concentrations.
ISSN:2227-9040