Adsorption Mechanism and Sensing Characteristics of In2O3-based Sensor Based on NOX Detection in Thermal Power Plants

NOx gas from thermal power generation can cause serious harm to the ecological environment and public health. Therefore, it is crucial to detect NOx gas from thermal power generation. In this paper, intrinsic In2O3 and Pt-In2O3 gas-sensitive materials were prepared by hydrothermal method, and the successful preparation of gas-sensitive materials was verified by three characterization means(SEM, XRD and XPS). Based on the constructed gas-sensitive platform, the concentration response and response recovery-time of Pt-In2O3 to NO and NO2 were tested. The response values of Pt-In2O3 for 30 ppm NO2 and NO were 7.7 and 10.3, respectively; the response-recovery time was 23/41 s and 18/46 s, respectively. In addition, the adsorption energy and density of states of each adsorption model were calculated based on the density functional theory to reveal the gas-sensing mechanism. The analyzed results show that Pt-In2O3 exhibits strong chemisorption of NOx. The Pt-In2O3 sensor fabricated in this paper is of great significance in realizing NOx detection in thermal power plants.