Zeolitic Imidazolate Frameworks (ZIF-8)-Induced Porous α-Fe 2 O 3 /SnO 2 /ZnO Heterostructures as Remarkable Gas-Sensing Materials for Acetone Detection

ZIF-8-induced porous α-Fe2O3/SnO2/ZnO heterostructures have been successfully fabricated via surface modification of one-dimensional (1D) rod-like Fe/Sn precursors by introducing ZIF-8 nanoparticles and subsequent annealing. The obtained composites are composed of regular and narrow size-distributed nanorods with average diameters of 90–105 nm and possessing a porous structure with a high specific surface area (197.96 m2/g). Compared with α-Fe2O3/SnO2 samples, optimal α-Fe2O3/SnO2/ZnO products exhibit higher gas response and selectivity for acetone at a lower working temperature of 240°C, with a response of 152 ppm to 100 ppm acetone that is approximately three times that of α-Fe2O3/SnO2 (~ 53.1), as well as rapid response and recovery times of 5 s and 3 s, respectively. Obviously, the decoration of ZIF-8 on the surface plays an essential role in adjusting the nucleation process of composite nanocrystals. The outstanding acetone-sensing property might be mainly attributed to the successful construction of tri-phase effective heterojunctions with abundant active sites on the surface/interface and accelerated electron migration along the 1D direction of the porous microstructures. The proposed α-Fe2O3/SnO2/ZnO heterostructures are promising sensitive materials for practical acetone detection.