Bi-doping induced oxygen vacancy engineering in LaFeO3 porous nanospheres for low-temperature and highly selective detection of n-butanol.

Bi-doped LaFeO3 porous microspheres with competitive gas-sensing performance toward n-butanol were successfully synthesized through a simple glutamic acid-assisted solvothermal method. This approach effectively regulated the oxygen-vacancy concentration in the material. Comprehensive characterization confirmed that Bi3+ was successfully incorporated into the LaFeO3 lattice, promoting partial Fe3+/Fe4+ conversion and generating abundant oxygen vacancies. Based on the optimized La0.94Bi0.06FeO3 sensor, the optimal operating temperature was significantly reduced to 150 ℃. At this temperature, the response to 10 ppm n-butanol reached 21, approximately seven times higher than that of pristine LaFeO3, with a detection limit as low as 101 ppb. Furthermore, the sensor demonstrated competitive selectivity, long-term stability, and humidity resistance. The improved sensing performance is likely associated with several factors, including oxygen vacancies, surface electronic modulation, and porous structure. This work presents an effective strategy for developing gas sensors based on high-performance perovskites by way of A cation doping.