Ultrafast synthesized LaFeO3-based oxides for highly sensitive n-propanol sensor

Abstract

Metal-organic frameworks (MOFs) have been used as sacrificial templates to fabricate porous metallic oxides. However, its usage is limited in preparing rare earth perovskite-type oxides, which are usually synthesized by sol-gel method. Herein, sol-gel route was employed to construct the uniform La/Fe MOFs, completed in several seconds at room temperature. The fabricated LaFeO3/La2O3, LaFeO3 and LaFeO3/Fe2O3 have porous structure, and the LaFeO3 possesses the largest specific surface area of 18.16 m2/g. Besides, abundant oxygen species exist on the surface of LaFeO3/La2O3 and LaFeO3, with percentages of 68.13 % and 64.15 % in O 1 s spectra, respectively. Benefit from the morphology structure and elements states, the LaFeO3-based sensor exhibits an ultra-high response of 258.4–100 ppm n-propanol, and the LaFeO3/La2O3-based sensor possesses the detection limit of 0.16 ppm, at a quite low working temperature of 100 ℃. This work provided a facile, universal, and adjustable approach to design perovskite metal oxides for ultra-sensitive detection of various gases.