Layered α-MoO3 nanoplates for gas sensing applications

Abstract

The synthesis of α-MoO₃ nanoplates with a unique well-faceted rectangular morphology produced by a polymeric solution route is presented. This versatile chemical route allowed the growth of layered nanoplates on different crystalline substrates to manufacture electronic/optoelectronic nanodevices. The α-MoO₃ crystalline phase was identified by both X-ray diffraction (XRD) and Raman spectroscopy. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the well-faceted rectangular layered nanoplates can be obtained depending on the fine control of the synthesis parameters due to the MoO₃ sublimation. Gas sensing measurements revealed that the α-MoO₃ nanoplates exhibit an enhanced response to NO₂, with sensor signals up to 50, combined with a low optimum operating temperature. In addition, the devices exhibited the highest selectivity to NO₂ relative to H₂, CO, and CH₄, which can be a consequence of the specific exposed surface plane. These results reveal that layered α-MoO₃ nanoplates are promising for use in the manufacturing of high-performance NO₂ gas sensor nanodevices.