A selective NH3 gas sensor based on Fe2O3–ZnO nanocomposites at room temperature

Gas sensors based on the Fe2O3–ZnO nanocomposites with different compositions of Fe:Zn was prepared by a sol–gel and spin-coating method. Morphology of the Fe2O3–ZnO nanocomposites was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD, D/max-rA) and energy dispersive X-ray analysis (EDX). The results of electrical and sensing measurement indicated that the sensor with Fe:Zn = 2% exhibited fairly excellent sensitivity and selectivity to NH3 at room temperature. The response and recovery time of the sensor were both less than 20 s. Finally, the mechanism for the improvement in the gas sensing properties was discussed.