Hollow MoS2/MoO3 Nanoreactors Optimize Triethylamine Oxidation Route for Boosted Sensing Performance

Abstract

Triethylamine (TEA), a strong irritating and combustible gas, is extremely dangerous to both human health and the surrounding environment. However, developing TEA sensors with high sensitivity and fast response remains a great challenge. Herein, we report hollow nanoreactors to optimize the TEA oxidation route for boosted sensing performance. Specifically, a group of MoS₂/MoO₃ (MSO-x) nanoreactors is controllably prepared through in situ partial oxidation strategy, using hollow hierarchical MoS₂ built from 2D nanosheets as a precursor. The MSO-2 with the highest concentration of oxygen vacancy exhibits both high sensitivity and fast response, in which the sensitivity to TEA (R_a/R_g = 54.2, 10 ppm) is about 5.4-fold higher than that of the pristine MoS₂, and the response time is decreased from 46 to 18 s at the working temperature of 200 °C. Finite element analysis demonstrates the increased TEA concentration inside the nanoreactor, which enhances the contact between TEA and active sites. Theoretical calculations and gas chromatograph–mass spectrometer results indicate that the MSO-2 nanoreactors toward TEA exhibit high selectivity on the pathway of acetaldehyde. The lower energy barrier on the MSO-2 implies a fast TEA oxidation rate, which consequently enhances the sensing performance. This work initially elucidates the TEA sensing mechanism from the perspective of the oxidization route, offering a valuable guidance for the rational design of high-efficiency sensing materials.