Interfacial charge-modulated carbon nanotube FET with a WS2 nanosheet sensing layer for room-temperature H2S detection

Abstract

Hydrogen sulfide (H2S) leakage is a critical threat to industrial safety, environmental monitoring, and human health, yet low-power detection of low-concentration H2S at room temperature remains challenging because gas-adsorption-induced electrical signals are typically weak and susceptible to environmental interference. Herein, we report a carbon-based field-effect transistor (FET) gas sensor that integrates a carbon nanotube (CNT) thin-film channel with a tungsten disulfide (WS2) nanosheet sensing layer. The key design concept is to decouple gas recognition from charge transport: WS2 nanosheets provide exposed adsorption sites and interfacial charge-transfer pathways for H2S, while the CNT network serves as a high-conductivity transduction channel for efficient signal amplification. Benefiting from this interfacial charge-modulation strategy, the sensor detects H2S down to 1 ppm at room temperature and exhibits good repeatability, selectivity, humidity tolerance, and batch-to-batch consistency. This work demonstrates a feasible route toward low-power, highly integrable FET-type H2S sensors and highlights the potential of coupling two-dimensional sensing layers with carbon-based transistor platforms for practical hazardous-gas monitoring.