Advances in two-dimensional layered materials for gas sensing

The emergence of two-dimensional (2D) layered materials with unique physiochemical properties and structure versatility has significantly boosted the development of gas sensing technology. This review paper explores recent advances in utilizing 2D materials, such as graphene, transition metal dichalcogenides (TMDs), black phosphorus, hexagonal boron nitride (h-BN), g-C₃N₄, MXenes, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs), for field-effect transistor (FET) and chemiresistive gas sensors. In addition to the unique properties contributing to the sensing performance, the key aspects of synthesis methods, sensing mechanisms, and sensing performance of 2D materials are systematically elaborated. Furthermore, the review highlights recent progress in performance optimization through material functionalization, heterostructure design, and material systems hybridization. Potential solutions to the key challenges, including scalability, reproducibility, selectivity, and environmental stability, are addressed to unlock the full potential of 2D materials in gas-sensing applications. By comprehensively compiling state-of-the-art developments in 2D layered materials for gas sensing, this review provides critical insights into the evolving landscape of sensor technologies and inspires new strategies for addressing critical environmental and industrial challenges.