Controlling the Morphology of Tellurene for a High-Performance H 2 S Chemiresistive Room-Temperature Gas Sensor.

A two-dimensional (2D) van der Waals material composed only of tellurium (Te) atoms-tellurene-is drawing attention because of its high intrinsic electrical conductivity and strong interaction with gas molecules, which could allow the development of high-performance chemiresistive sensors. However, the correlation between the morphologies and gas detection properties of tellurene has not yet been studied in depth, and few reports exist on tellurene-based hydrogen sulfide (H 2 S) chemiresistive sensors in spite of their strong interaction with H 2 S molecules. Here, we investigate the morphology-dependent H 2 S gas detection properties of tellurene synthesized using a hydrothermal method. To tailor the morphologies of tellurene, the molecular weight of the surfactant was controlled, revealing that a 1D or 2D form was synthesized and also accompanied with the high crystallinity. The 1D tellurene-based chemiresistive sensor presented superior H 2 S detection properties compared to the 2D form, achieving a gas response (R g /R a ) of ~38, even at room temperature. This outstanding performance was attributed to the high intrinsic electrical conductivity and high specific surface area of the resultant 1D tellurene.