Al-doped ZnO nanorods arrays on NiO nanofibers to construct a typical ZnO-NiO hetero-nanostructure on Al2O3 substrate have been obtained by electrospinning and hydrothermal methods. The sensors based on this hetero-nanostructures exhibit high selectivity and sensitivity towards triethylamine gas under operating temperature of 250 degrees C, and Al doping has a great influence on the air-sensitive performance of the sensors. Our results indicate that the ZnO-NiO hetero-nanostructure is a potential candidate for gas sensors with good performances for practical applications. (C) 2014 AIP Publishing LLC.