Rational interaction between the aimed gas and oxide surfaces enabling high-performance sensor: The case of acidic α-MoO3 nanorods for selective detection of triethylamine

The rational interaction between the oxide surfaces and aimed gas is favorable for enhancement in gas-sensing (including rapid response and recovery rate, remarkable response value, and excellent selectivity). Herein, we have prepared acidic α-MoO₃ nanorods through a facile hydrothermal route. The as-obtained MoO₃ nanorods possess about 10 μm in length and around 200–300 nm in diameter, respectively. The gas sensor fabricated using these MoO₃ nanorods exhibits an apparent response to triethylamine (TEA) vapor with an actual detection concentration as low as 0.1 ppm at its optimal working temperature of 300 °C. The response time for detecting 100 ppm TEA is only 4 s, and the recovery time is less than 2 min (88 s). Moreover, the sensor shows an extremely remarkable selectivity towards TEA against other interfering gases, such as methanol, ethanol, isopropanol, acetone, toluene, and ammonia. The impressive TEA sensing of these MoO₃ nanorods could be determined by suitable interaction between TEA molecules and the MoO₃ surfaces (including base/acid attractive force, highly active lattice oxygen for catalytical oxidation of TEA, and fast adsorption/desorption kinetics at certain temperature). This paper provides an avenue for designing high-performance gas sensor from perspective of understanding the interaction between aimed gas and material surfaces.