Orthorhombic Phase MoO₃ Nanobelts Gas Sensor for Ultrasensitive Detection of Triethylamine

In view of the poor sensitivity and upper detection limit of triethylamine gas sensors, high performance triethylamine sensor was prepared by adjusting the crystalline phase of MoO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>. In this work, the orthorhombic phase MoO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> nanobelts were synthesized through hydrothermal method and used for the detection of triethylamine. The experimental outcomes indicate that the orthorhombic phase MoO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> gas sensor exhibits the peak responsiveness, which reaches 774.47 when the concentration of triethylamine is 100 ppm at 220°C accompanied by a theoretical detection threshold as minute as 10 ppb. The orthorhombic phase MoO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> sensor has superior selectivity for triethylamine stemming from the robust Lewis acid-base interplay with MoO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and triethylamine and the C-N of triethylamine is easily broken. Finally, the sensing mechanism of orthorhombic phase MoO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> gas sensor is deeply analyzed. Since orthorhombic phase MoO<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> possesses a narrow band gap 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.