Three-Dimensional MoS<sub>2</sub>/MXene Heterostructure Aerogel for Chemical Gas Sensors with Superior Sensitivity and Stability
Seulgi Kim, Hamin Shin, Jaewoong Lee, Chungseong Park, Yunhee Ahn, Hee‐Jin Cho, Seoyeon Yuk, Jihan Kim, Dongju Lee, Il‐Doo Kim
Abstract
The concept of integrating diverse functional 2D materials into a heterostructure provides platforms for exploring physics that cannot be accessed in a single 2D material. Here, physically mixing two 2D materials, MXene and MoS 2, followed by freeze-drying is utilized to successfully fabricate a 3D MoS 2 /MXene van der Waals heterostructure aerogel. The low-temperature synthetic approach effectively suppresses significant oxidation of the Ti 3 C 2 T x MXene and results in a hierarchical and freestanding 3D heterostructure composed of high-quality MoS 2 and MXene nanosheets. Functionalization of MXene with a MoS 2 catalytic layer substantially improves sensitivity and long-term stability toward detection of NO 2 gas, and computational studies are coupled with experimental results to elucidate that the mechanism behind enhancements in the gas-sensing properties is effective inhibition of HNO 2 formation on the MXene surface, due to the presence of MoS 2 . Overall, this study has a great potential for expansion of applicability to other classes of two-dimensional materials as a general synthesis method, to be applied in future fields of catalysis and electronics.