fig6

Figure 6. Facet-dependent NO₂ sensing performance and mechanistic illustration of atomically dispersed Pt-sensitized CeO₂. (A) Sensor response of Pt single-atom (Pt_SA)-(100)CeO₂ to varying NO₂ concentrations at room temperature; (B) Response and recovery time of Pt_SA-(100)CeO₂ for 5 ppm NO₂;. (C) Response behavior of Pt_SA-(111)CeO₂ toward different NO₂ levels under identical conditions; (D and E) Sensing performance of both facet-engineered samples toward 30 ppm NO₂ under varying O₂ concentrations and relative humidity; (F and G) Proposed surface reaction models illustrating NO₂ adsorption and activation pathways on Pt_SA-(100)CeO₂ and Pt_SA-(111)CeO₂, respectively. Reproduced under the terms of the CC-BY Creative Commons Attribution 4.0 International licence (https://creativecommons.org/licenses/by/4.0)^[52]. Copyright 2024, The Authors, published by Wiley-VCH. R_a/R_g: Resistance in air/resistance in test gas; Pt_SA: atomically dispersed Pt; FLP: frustrated Lewis pair.