Loose Ag-doped LaFeO₃ nanotubes-based gas sensor for excellent acetic acid sensing

The efficient and reliable monitoring of acetic acid is significant to environmental protection and human healthcare. LaFeO3 is a potential sensing material for acetic acid with its good sensitivity and high plasticity. To further improve the sensing properties of LaFeO ₃ to meet the requirements of applications, we successfully utilized the facile electrospinning technique to fabricate a series of acetic acid-sensitive Ag-doped (0-5 mol%) LaFeO ₃ nanotubes. The systematic characterization shows that the appropriate content (4 mol%) of Ag doping can effectively ameliorate the material morphology to realize loose porous structures. Meanwhile, the sensitization effect of Ag and ameliorated morphology significantly enhance the gas sensing properties of LaFeO ₃ to acetic acid vapor. The optimal Ag-doped LaFeO ₃ (4 mol%) loose nanotubes-based gas sensor results in a detection limit of 0.5 ppm and 3.6-fold enhancement of the response to 100 ppm acetic acid compared with the pure LaFeO ₃ compact nanotubes at a low operating temperature (150°C). It also exhibits excellent selectivity to acetic acid and good long-term stability. Therefore, Ag-doped LaFeO ₃ can be regarded as a promising material for sensing acetic acid in practical applications. Finally, the mechanism of enhanced gas-sensing properties is discussed.