Three-Dimensional MoS2/MXene Heterostructure Aerogel for Chemical Gas Sensors with Superior Sensitivity and Stability

• Published in: ACS nano Vol. 17; no. 19; pp. 19387 - 19397
• Main Authors: Kim, Seulgi, Shin, Hamin, Lee, Jaewoong, Park, Chungseong, Ahn, Yunhee, Cho, Hee-Jin, Yuk, Seoyeon, Kim, Jihan, Lee, Dongju, Kim, Il-Doo
• Format: Journal Article
• Language: English
• Published: American Chemical Society 10.10.2023
• Subjects: Ti3C2T x MXene; heterostructures; MoS2; aerogel; gas sensors
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.3c07074

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 MoS2, followed by freeze-drying is utilized to successfully fabricate a 3D MoS2/MXene van der Waals heterostructure aerogel. The low-temperature synthetic approach effectively suppresses significant oxidation of the Ti3C2T x MXene and results in a hierarchical and freestanding 3D heterostructure composed of high-quality MoS2 and MXene nanosheets. Functionalization of MXene with a MoS2 catalytic layer substantially improves sensitivity and long-term stability toward detection of NO2 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 HNO2 formation on the MXene surface, due to the presence of MoS2. 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.