High-response n-butanol gas sensor based on ZnO/In2O3 heterostructure

In this study,ZnO/In2O3-heterostructured nanosheets were prepared using a one-step hydrothermal method.The effects of ZnO content on the gas-sensing performance were discussed,with ZnO/In2O3-2 exhibiting the highest performance among the prepared sensors.The response of ZnO/In2O3-2 to n-butanol was 302 at 26℃,which was 11.93 times higher than that of pure In2O3.Among the eight tested gases,ZnO/In2O3-2 displayed the highest response to n-butanol.Moreover,the lower detection limit of the ZnO/In2O3nanosheets was reduced from 10 × 10-6to 0.1 × 10-6(for pure In2O3nanosheets)toward n-butanol.This is because the doping of Zn2+increases the number of oxygen vacancies on the sensor surface and allows the formation of an n-n heterostructure between ZnO and In2O3,which increases the initial resistance of the sensor.