Solution combustion synthesis and enhanced gas sensing properties of porous In2O3/ZnO heterostructures

Abstract

Self-assembled porous In2O3/ZnO heterostructures were prepared by a low temperature solution combustion synthesis method, and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The results indicate that the as-synthesized porous In2O3/ZnO heterostructures were constructed from a large number of In2O3 and ZnO nanoparticles and showed high gas sensing performance toward Cl2. Compared with pure ZnO and other heterostructure sensors, the porous In2O3/ZnO heterostructures with an appropriate molar ratio of In2O3:ZnO exhibited highly enhanced gas sensing performances toward Cl2. An extremely high sensitivity of 6610 could be reached when exposed to 50 ppm Cl2 at 370 °C; also, In2O3/ZnO heterostructures showed high selectivity toward Cl2. Furthermore, the gas sensing mechanism was discussed.