Ab-Initio Study on Vertical and Lateral Heterostructures of WS₂–MoS₂ for Gas Sensing

The discovery of graphene has motivated research in the field of novel 2-D materials. A wide variety of 2-D materials with tunable electronic properties show promise in the development of gas sensors for their applications in medical devices and environmental monitoring. In this work, the first principle calculation based on density functional theory was carried out to study the adsorption of NO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>, NO, NH<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>, CO, and H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S on pristine WS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and its vertical and lateral heterostructures with MoS<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>. The formation of heterostructures led to significant improvement in adsorption energy. Vertical heterostructures have shown the highest adsorption energy towards CO.