High-speed and Sub-ppm Detectable Tellurene NO₂ Chemiresistive Room-Temperature Sensor under Humidity Environments

Two-dimensional material, tellurium, composed of tellurium, has emerged as a promising material for NO₂ gas sensing due to its superior intrinsic electrical conductivity and strong affinity to NO₂. However, the majority of literature on tellurene-based gas sensors has primarily focused on NO₂ detection performances under dry condition, despite the importance of considering humidity-dependent detection properties for practical gas sensing applications. Here, we explore NO₂ detection properties of tellurene-based chemiresistive gas sensor devices under humidity environments at room temperature. The resultant tellurene synthesized via a hydrothermal route presents 2D flake-like morphologies with highly crystalline hexagonal structures. The obtained tellurene chemiresistive sensor devices exhibit a good NO₂ gas response of 35% with a fast response time of 14 s, under dry conditions. Interestingly, our tellurene-based sensor devices also present the humidity-independent NO₂ gas detection performances while achieving a fast response time. These outstanding detection performances are likely due to intrinsically superior electrical conductivity and structural stability of tellurene in air.