Enhancing the responsiveness of porous LaFeO3 microspheres to ethanol under high humidity.

Perovskite oxide has good sensitivity to VOCs gases, but its gas-sensitive properties are negatively affected by high humidity, thereby limiting its potential application in respiratory gas detection. This study focuses on synthesizing porous LaFeO3 of perovskite type used a dual-process method involved hydrothermal synthesis with thermal treatment. The morphology and evolution of porous LaFeO3 microspheres was studied. The LaFeO3 sensors exhibited p-type gas-sensitive behavior with notable selectivity for respiratory gases. The LaFeO3 sensor represented a significant response value of 9.7 to a 100 ppm C2H5OH concentration, with a rapid response/recovery time of 8 s/9 s at 300 °C. The sensor demonstrated a high response (S = 4.2) and a low detection limit of 100 ppb at 90% relative humidity. The superior sensor performance was due to the porous surface structure of LaFeO3 microspheres, which improved the gas diffusion channels and reaction sites with microspheres. The density of states map revealed a strong orbital hybridization between C2H5OH and LaFeO3, resulted in a calculated adsorption energy of − 1.18 eV, signified a strong adsorption affinity in line with the experimental results. [ABSTRACT FROM AUTHOR]