Orthorhombic Phase MoO3 Nanobelts Gas Sensor for Ultrasensitive Detection of Triethylamine

In view of the poor sensitivity and upper detection limit of triethylamine (TEA) gas sensors, a high-performance triethylamine sensor was prepared by adjusting the crystalline phase of Molybdenum trioxide (MoO3). In this work, the orthorhombic phase MoO3 nanobelts were synthesized through the hydrothermal method and used for the detection of triethylamine. The experimental outcomes indicate that the orthorhombic phase MoO3 gas sensor exhibits peak responsiveness, which reaches 774.47 when the concentration of triethylamine is 100 ppm at $220~^{\circ }$ C, accompanied by a theoretical detection threshold as minute as 10 ppb. The orthorhombic phase MoO3 sensor has superior selectivity for triethylamine stemming from the robust Lewis acid-base interplay with MoO3 and triethylamine, and C-N of triethylamine is easily broken. Finally, the sensing mechanism of the orthorhombic phase MoO3 gas sensor is deeply analyzed. Since orthorhombic phase MoO3 possesses a narrow bandgap and small size effect, and has a high adsorption energy for triethylamine, the gas sensor exhibits excellent performance. The strategic design of crystalline phase modulation serves as a pivotal approach to enhancing the properties of gas sensors.