ScholarWorks@중앙대학교

초록

Increasing industrialization has led to a rise in nitrogen dioxide (NO2) emissions, necessitating highly sensitive and selective gas sensors for air quality monitoring. Transition metal dichalcogenides (TMDs), particularly tin disulfide (SnS2), have gained attention owing to their tunable electronic properties and high surface reactivity. This paper proposes a chlorine-passivated SnS2 flower-like nanosheet (FLNS) gas sensor, synthesized via a single-step chemical vapor deposition process using SnCl4·5 H2O as a precursor, which introduces chlorine radicals that modulate the surface properties of SnS2. Structural and compositional characterization via X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet–visible spectroscopy, and X-ray photoelectron spectroscopy confirm the formation of Cl-passivated SnS2 FLNSs. Gas sensing performance evaluation reveals a remarkable sensor response of 320.32 and a recovery rate of 91.38 % for 10 ppm NO2, surpassing previously reported SnS2-based sensors. Chlorine passivation plays a key role in enhancing NO2 adsorption, possibly owing to surface charge modulation and defect engineering, leading to improved sensor stability, selectivity, and response. The proposed device achieves a limit of detection of 0.15 ppb, the lowest among SnS2-based NO2 sensors, and stable detection of 100 ppb NO2 at ∼25 °C. The ultra-fast one-minute recovery underscores the impact of chlorine passivation in accelerating NO2 desorption. These findings establish Cl-passivated SnS2 FLNSs as a promising material for next-generation NO2 sensors with superior sensitivity and rapid recovery, suitable for industrial air quality monitoring.

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