Near‐Room‐Temperature Ethanol Gas Sensor Based on Mesoporous Ag/Zn–LaFeO3 Nanocomposite

The rational design of heterojunction between different metal oxides with mesoporous structures has attracted tremendous attention due to their special physicochemical properties and vital importance for practical applications. In this paper, mesoporous Ag/Zn–LaFeO3 nanocomposite is successfully synthesized through a facile nanocasting technique using KIT‐6 as a hard template in sol–gel route and used as sensing materials to achieve an exceptionally sensitive and selective detection of trace ppm‐level ethanol. The obtained composite possesses high surface area and exhibits excellent sensing response (64.2 for 100 ppm) to ethanol at near‐room with relatively fast response/recovery time. When tested with the concentrations as low as 5 ppm, it also shows a remarkably high selectivity to the ethanol, but only minor responses to other interfering gases. These enhanced gas‐sensing properties are attributed to the combination of mesoporous nanostructure and Ag/Zn–LaFeO3 heterogeneous composites. Perovskite type metal oxide semiconductors are developed for application of gas sensors due to their numerous favorable physical/chemical properties. LaFeO3 shows considerably sensitive to reducing gases, but it still has some deficiencies. Mesoporous Ag/Zn–LaFeO3 nanocomposite synthesized through facile nanocasting technique is used as a sensing material to achieve sensitive and selective detection of trace ppm‐level ethanol at near‐room temperature.