Room temperature ultrasensitive ppb-level H2S SAW gas sensor based on hybrid CuO@V2C MXene van der Waals heterostructure

초록

The analysis of exhaled human breath has great significance for early noninvasive diagnosis. However, highly sensitive and selective detection against part-per-billion (ppb) biomarkers in exhaled human breath (RH >= 80%) at room temperature remains a challenge. SnO2 quantum wires (QWs) consisting of a few hundreds to thousands of atoms are demonstrated to be promising for low-power consumption gas sensors to achieve an on-chip electronic nose. Here, we propose a low-temperature doping strategy in realizing the synthesis of the transition metal (Mn, Cr, V)-doped SnO2 QWs. The doped SnO2 QWs with sub-4 nm diameters as chemiresistive gas sensors enable us to improve the adsorption activities, achieving enhanced room-temperature sensing properties toward the trace biomarkers (e.g., acetone, formaldehyde, and H2S) with the state-of-the-art limit of detection of 2.6, 1.5, and 1.3 ppb, respectively. These transition metal-doped SnO2 QWs are then integrated as a sensor array, enabling gas identification at different relative humidities by using machine learning algorithms. Moreover, systematical characterizations combined with density functional theory (DFT) calculations are conducted to figure out the effect of doping on SnO2 QW properties for the sensitive and selective ppb-level gas detection. The engineering of transition metal-doped SnO2 QWs helps us to extend the library for the design of low-power consumption gas sensors in more broad applications.

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