Mixed-dimensional van der Waals heterostructure enabled gas sensors: fundamentals and applications

The recent advances in the field of gas sensing technology by the introduction of van der Waals (vdW) heterostructures have attracted worldwide attention. The integration of atomically thin layers of 2D materials with other materials significantly improves the molecular detection capability due to high surface area, tunable junction properties, and their synergistic effects. Therefore, a deeper understanding of the exciting physics of vdW heterostructures is of considerable importance for developing advanced and versatile gas sensors. As a result, here we present a critical review highlighting the recent developments in gas sensors with a particular emphasis on vdW heterostructures. We provide a deep understanding of different kinds of 2D/0D, 2D/1D, 2D/2D, and 2D/3D heterostructures and their sensing mechanism towards realizing high-performance practical gas sensors. Finally, we summarize the article by stressing the challenges and giving our perspective on the applications of vdW heterostructures in developing next-generation gas sensors.