Plasmonic Au-enabled photoenhanced room temperature NO2 sensing of 2D SnS2-heterostructure via single-step mechanochemical synthesis

• Published in: Journal of alloys and compounds 2025-01, Vol.1010, p.177562, Article 177562
• Main Authors: Zhang, Min, Li, Zhong, Tang, Tao, Ou, Rui, Zhang, Bao Yue, Ma, Qijie, Cheng, Yin Fen, Liang, Yi, Zhuang, Jing Hao, Zhang, Wen Ji, Jannat, Azmira, Haidry, Azhar Ali, Ou, Jian Zhen
• Format: Article
• Language: English
• Subjects: 2D materials; Au/SnS2; LSPR; NO2 sensor; UV light
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2024.177562

The development of high-performance gas sensors for NO2 detection is critical due to its harmful effects on human health and environment. Tin disulfide (SnS2), with its layered structure akin to transition metal dichalcogenides (TMDs), shows potential for NO2 sensing. However, SnS2-based sensors typically exhibit weak response and incomplete recovery at room temperature. In this study, we propose 2D SnS2 nanosheets modified with gold nanoparticles (Au-NPs) by a single-step mechanochemical synthesis, in which photoelectric sensors depend on the light absorption properties of the sensitive material, thus Au-NPs with LSPR effect coupled with SnS2 can enhance the absorption capacity of the composite in the UV light band. The higher light absorption efficiency means that more electrons and holes can be produced under light excitation, and the holes can react with the NO2 adsorbed on the surface of the material, speeding up the desorption of NO2. As compared to the unmodified SnS2 sensor, the response values of Au/SnS2 sensor to 10 ppm NO2 at room temperature increased from 7.74 to 16.01, while the response/recovery time reduced from 169/201 s to 98/154 s. Moreover, the Au/SnS2 sensor can detect low concentrations of NO2 (50 ppb) with excellent repeatability, selectivity, and long-term stability at room temperature. This study demonstrates that integrating Au-NPs modification with UV photo-assistance is a viable strategy for developing high-performance room temperature gas sensors. [Display omitted] •2D SnS2 nanosheets modified with gold nanoparticles by a single-step mechanochemical synthesis.•Thanks to the electron sensitization, chemical sensitization, as well as LSPR effect introduced by Au-NPs, the Au/SnS2 sensor shows high response to 10 ppm NO2 even at room temperature.•The sensor exhibits highly selective to NO2 and excellent long-term stability.