A yolk-double-shelled heterostructure-based sensor for acetone detecting application.

A high-performance gas-sensing material combines the advantageous features of high specific area and fast electron transport. These features are heavily dependent on the engineered configuration design and interfacial construction of the material. Here, a synthesis method is presented which combines the two requirements by producing porous nickel oxide-zinc oxide (NiO-ZnO) hybrid yolk-double-shelled spheres. The performance of the hybrid material was compared to a more conventional single-component (NiO) based material. The results showed that the sensor based on the hybrid material exhibited not only a higher response (7.5), but also faster response and recovery speeds (8/13 s), demonstrating its potential application in high-performance gas sensors. The enhanced sensing performance is attributed to the unique yolk-double-shelled structure with porous shells and the synergic electronic interaction between p-type NiO and n-type ZnO.