Influence of dipole moment on the VOC sensing properties of BiFeO3 microspheres: Addressing the selectivity towards acetone

The selectivity of a chemi-resistive sensor towards a particular gas/vapor depends on various factors and needs to be explained more precisely. Herein, the selective detection of acetone by hydrothermally prepared BiFeO3 microspheres has been explained correlating the dipole moment of tested volatile organic compounds (VOCs) with the sensing properties followed by the dipole-dipole interaction between sensing material and target VOCs. Acetone with the highest dipole moment (2.91 D) compared to other interfering vapors shows the highest response of 10±1 for 50 ppm operating at 400 °C governed by the strongest dipole-dipole interaction. Moreover, a moderate degree of repeatability shown in 7 cycles, long-term stability tested for 90 days along with the microstructural and compositional stability tested before and after the sensing tests, and consistency in sensing performance even in humid atmospheres point toward the potential of the prepared material as a reliable acetone sensor along with proper validation of its selectivity issue. [Display omitted] •Phase pure BiFeO3 microspheres were synthesized in hydrothermal route.•Selectively detect low ppm acetone (R∼1.45, 5 ppm).•Dipole moment of VOCs influenced the sensing.•Dipole – dipole interaction accurately explains selectivity towards acetone.