Zhihao Zhang,Shendan Zhang,Chunjie Jiang,Haichuan Guo,Fengdong Qu,Yuichi Shimakawa,Minghui Yang
Distinguishing toxic gases among the various volatile sulfur compounds (VSCs) is of significant practical value for atmospheric and environmental pollution monitoring, industrial monitoring, and even for medical diagnostics (where VSCs are indicators of diseases). The particular challenge lies in the detection and discrimination of sulfur-containing gases such as dimethyl disulfide (DMDS), methyl sulfide (DMS), hydrogen sulfide (H 2 S), and carbon disulfide (CS 2 ) is of value. Herein, single-phase perovskite-type LnFeO 3 nanoparticles were prepared by the citrate sol-gel method. Their gas sensing characteristics regard to the four typical VSCs were investigated. We found that the gas response of the p-type semiconductor LnFeO 3 gas sensors to the four typical VSCs are significantly different. In addition, the sensors offer high performance, good tolerance to environmental changes and long-term stability for detecting VSCs gas at an operating temperature of 210 °C. A new design of sensor array was realized by integrating a series of LnFeO 3 materials, which revealed excellent recognition ability for various VSCs, showing promise for real time monitoring.
The early detection of lung cancer by breath analysis has attracted more and more attention. In this work, high-performance LnFeO 3 (Ln = Nd, Dy, Er) based isopropanol sensors were synthesized by microwave-assisted hydrothermal method. X-ray diffraction, field-emission scanning electron microscope, transmission electron microscope, and UV–visible-near infrared absorption spectrometer were used to analyze the material phase composition, microstructure, and other physical properties. The sensing performance was tested by using a four-channel gas testing chamber. The sensors were tested with low concentrations of isopropanol at high humidity to simulate a real human exhaled breath environment. The low binding energy of the Ln-O bond makes it easy to have chemical reactions, which leads to excellent isopropanol sensing performance. Finally, the gas sensing mechanism of the LnFeO 3 sensor was discussed.