Acetone sensing characteristics of TiO2-LaFeO3 nanocomposites

To enhance the acetone sensing capabilities of LaFeO3 nanoparticles for practical applications in breath analysis, commercial n-type rutile TiO2 nanoparticles were utilized as additives and directly mixed with LaFeO3 nanoparticles synthesized via a sol-gel method. The obtained TiO2-LaFeO3 nanocomposites were characterized by XRD, SEM, BET, and XPS. Compared to pure LaFeO3 nanoparticles, the resulting TiO2-LaFeO3 nanocomposites exhibited higher surface reactivity, as evidenced by their larger specific surface areas and higher oxygen vacancy contents. The introduction of TiO2 also facilitated the formation of p-n heterojunctions, which enhanced the regulation of acetone molecules on internal carrier conduction within the nanocomposites. Therefore, the TiO2- LaFeO3 nanocomposites demonstrated improved acetone sensing performance, including higher vapor response values, selectivity, and faster response/recovery speeds. Among the series of nanocomposites, those with an addition of 10 wt% TiO2 exhibited the highest vapor response value (37.3 to 100 ppm) and the greatest selec-tivity against methanol and ethylene glycol at the prime operating temperature of 144 degrees C.

Automated summary

In this study, commercial TiO2 nanoparticles were used as additives and directly mixed with LaFeO3 nanoparticles to prepare TiO2-LaFeO3 nanocomposites. The resulting nanocomposites showed higher surface reactivity and oxygen vacancy contents compared to pure LaFeO3 nanoparticles, and the introduction of TiO2 facilitated the formation of p-n heterojunctions. Therefore, TiO2-LaFeO3 nanocomposites demonstrated enhanced acetone sensing performance.