One-step hydrothermal fabrication of nanosheet-assembled NiO/ZnO microflower and its ethanol sensing property

In this work, we report a simple synthesis of hierarchical flower-like NiO/ZnO heterostructure consisting of numerous nanosheets via a facile one-step hydrothermal method. The gas-sensing results reveal that the NiO/ZnO composite based sensor presents excellent properties towards ethanol such as high gas response and good repeatability. The excellent performances are predominantly ascribed to the p-n heterojunction strengthening at the interface between p-type NiO and n-type ZnO, which causes the change of depletion layer and potential barrier height. Moreover, the unique hierarchical architectures may play an evenly important role in the surface sensing reaction.