Cho, Young Ju Kwon, Yong Jung Jin, Sunghwan Choi, Hyeunseok Lee, Jung-Hoon Yang, Seung-Min Choi, Sun-Woo Jeong, Young Kyu 2024-01-19T12:01:39Z 2024-01-19T12:01:39Z 2022-04-29 2022-06 0304-3894 https://pubs.kist.re.kr/handle/201004/115169 In humid conditions, water vapor can easily neutralize the surface active sites of metal oxide sensors, leading to a lowering in the sensitivity of the gas sensor and a resultant inaccurate signal in practical applications. Herein, we present a new hybrid sensor by introducing a two-dimensional calcium silicate (CS) nanosheet as a water trapping layer in SnO2 nanowires. Unlike the heavily wrinkled and aggregated morphology of conventional CS nanosheets, our nanosheet in the hybrid material is ultrathin and flat. Moreover, it was grown in the empty spaces between the spider-web-like networks of SnO2 nanowires without covering the nanowire surface. These two morphological features improve moisture trapping with minimal reduction in the active sensing area. Consequently, stable and sensitive gas detection under humid conditions was achieved in this hybrid sensor. The superior humidity-independent sensing is ascribed to the preferential adsorption of water molecules on hydroscopic CS nanosheets through the hydrogen bond. Based on density functional theory calculations, we determined that the improved gas response is driven by the additional formation of oxygen vacancy in SnO2 due to the diffusion of aliovalent Ca ions from the CS nanosheet. English Elsevier BV Two-Dimensional calcium silicate nanosheets for trapping atmospheric water molecules in humidity-immune gas sensors Article 10.1016/j.jhazmat.2022.128671 1 JOURNAL OF HAZARDOUS MATERIALS, v.432 JOURNAL OF HAZARDOUS MATERIALS 432 N scie scopus 000782127600006 Engineering, Environmental Environmental Sciences Engineering Environmental Sciences & Ecology Article SNO2 NANOWIRES HYDRATE NANOCOMPOSITES TOBERMORITE IMPROVEMENT ATTACHMENT DENSITY MODEL LAYER Calcium silicate nanosheet Hybrid gas sensor Humidity independence SnO2 nanowires Water-trapping layer