Interface and Bimetallic Sites Synergistic Regulation of CuFe2O4/Fe2O3 Nanotubes for High Response Detection of 2-Chloroethyl Ethyl Sulfide Gas

Abstract Mustard gas is an extremely dangerous chemical substance, and its leakage or misuse poses a serious threat to the environment and public health. It is challenging to develop a fast, efficient, and real-time sensor for the detection of the mustard gas simulant (2-chloroethyl ethyl sulfide = 2-CEES). In this study, CuFe2O4/Fe2O3 nanotubes were assembled in situ via a controllable solvothermal method. Structural characterization confirms that the CuFe2O4/Fe2O3 nanotubes possesses bimetallic active sites and abundant heterointerfaces, which synergistically enhance the sensing performance of the material. At an operating temperature of 170 °C, the as‑prepared CuFe2O4/Fe2O3 nanotubes exhibit excellent sensing performance toward 100 ppm 2‑CEES, with a high response value of 58.6 and a short response/recovery time of only 6.5/583 s. Additionally, this material possesses good repeatability and long-term stability. The sensitization and interface enhancement mechanism of CuFe2O4/Fe2O3 to 2-CEES was investigated by combining characterization techniques, including X-ray photoelectron spectroscopy, gas chromatography-mass spectrometry, in situ diffuse reflectance infrared Fourier transform spectroscopy, and density functional theory calculations. This work lays a research foundation for the preparation of sensing nanotube array materials with bimetallic sites and abundant heterointerfaces.