High‐response n‐butanol gas sensor based on ZnO/In 2 O 3 heterostructure

In this study, ZnO/In 2 O 3 ‐heterostructured nanosheets were prepared using a one‐step hydrothermal method. The effects of ZnO content on the gas‐sensing performance were discussed, with ZnO/In 2 O 3 ‐2 exhibiting the highest performance among the prepared sensors. The response of ZnO/In 2 O 3 ‐2 to n‐butanol was 302 at 26 °C, which was 11.93 times higher than that of pure In 2 O 3 . Among the eight tested gases, ZnO/In 2 O 3 ‐2 displayed the highest response to n‐butanol. Moreover, the lower detection limit of the ZnO/In 2 O 3 nanosheets was reduced from 10 × 10 −6 to 0.1 × 10 −6 (for pure In 2 O 3 nanosheets) toward n‐butanol. This is because the doping of Zn 2+ increases the number of oxygen vacancies on the sensor surface and allows the formation of an n–n heterostructure between ZnO and In 2 O 3 , which increases the initial resistance of the sensor.