Constructing p–p heterojunction with PANI to improve the acetone sensing performance of LaFeO3 nanoparticles

LaFeO 3 nanoparticles were synthesized by a sol–gel method and directly mixed with commercial PANI powders to form a series of PANI–LaFeO 3 nanocomposites according to the mass ratio PANI to LaFeO 3 as 1%, 3%, and 5%. XRD and SEM results reveal that the LaFeO 3 nanoparticles in the orthorhombic crystal structure are distributed on the surface of the PANI bulk. The nanocomposites-based sensors showed better acetone sensing performance than the pure LaFeO 3 , which was ascribed to the increased amount of oxygen adsorbed on the surface of LaFeO 3 nanoparticles and the enhanced modulation of the internal carrier transfer within the nanocomposites. The sensor based on the PANI–LaFeO 3 nanocomposite with a mass ratio of 3% showed the highest response (36.6) to 100 ppm acetone with the best selectivity against methanol, ammonia, and ethylene glycol at the prime working temperature of 120℃. Therefore, the PANI–LaFeO 3 nanocomposite is a promising acetone sensing material with low energy consumption.