High sensitivity and low detection limit of acetone sensor based on NiO/Zn2SnO4 p-n heterojunction octahedrons

In this work, we successfully prepare the octahedral NiO/Zn2SnO4 p-n heterostructure by a simple hydrothermal synthesis and subsequent wet impregnation process. The microscopic morphology characterization results show that the as-prepared composites are uniformly dispersed and have an octahedral structure with a size of 3-5 ?m. The gas devices are fabricated and their sensing performances are investigated systematically. The response and selectivity of NiO/Zn2SnO4 composites to acetone have been significantly improved than that of pure Zn2SnO4. Moreover, the response of the sensor to 100 ppb acetone is 1.4 at 300 ?C, indicating that the detection limit is less than 100 ppb. The enhancement in sensing properties of composites is largely due to the p-n heterojunction formed by NiO and Zn2SnO4, which causes the transfer of carriers and the catalytic effect of NiO.

Automated summary

In this study, the octahedral NiO/Zn2SnO4 p-n heterostructure was successfully prepared through simple hydrothermal synthesis, showing improved sensing performance compared to pure Zn2SnO4. The enhanced sensing properties are mainly attributed to the formation of a p-n heterojunction between NiO and Zn2SnO4, facilitating carrier transfer and catalytic effects. The gas sensor exhibited a response of 1.4 to 100 ppb acetone at 300℃, indicating a detection limit of less than 100 ppb.