A heterojunction composite of Bi2Se3 nanosheets and MoO3 nanobelts for a high-performance triethylamine sensor

The combination of metal oxides and 2D nanomaterials demonstrated remarkable enhancement in gas sensing performance. In this work, a heterojunction composite of 2D Bi2Se3 nanosheets and 1D MoO3 nanobelts was first synthesized by a simple and low-cost strategy. Significantly, the Bi2Se3/MoO3-2 composite with a mass ratio of 2 : 1 for MoO3 to Bi2Se3 exhibited a pronounced response of 151 to 10 ppm TEA at 240 degrees C, which was five times higher than that of MoO3. Moreover, the sensor showed excellent selectivity to triethylamine (TEA), long-term stability (96% response retention after 30 days), and a low detection limit of similar to 5.5 ppb. The enhanced TEA sensing performance can be attributed to the formation of the n-n heterojunction between Bi2Se3 and MoO3, which provides more active sites for the reaction of TEA molecules and improves the electron carrier transfer from Bi2Se3 to MoO3. This work demonstrates the potential of the Bi2Se3 nanosheet and MoO3 nanobelt composite as an ultrasensitive sensor for TEA detection.