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

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.