HS detection at low temperatures by CuO/FeO heterostructure ordered array sensors.

2D heterostructures are promising gas sensor materials due to their surface/interface effects and hybrid properties. In this research, CuO/FeO heterostructure ordered arrays were synthesized using an electrodeposition method for HS detection at low temperatures. These arrays possess a periodic long range ordered structure with horizontal multi-heterointerfaces, leading to superior gas sensitivity for synergistic effects at the heterointerfaces. The sensor based on the CuO/FeO heterostructure ordered arrays exhibits a dramatic improvement in HS detection at low temperatures (even as low as -15 °C). The response is particularly significant at room and human body temperatures since the conductivity of the arrays can change by up to three orders of magnitude in a 10 ppm HS atmosphere. These good performances are also attributed to the formation of metallic CuS conducting channels. Our results imply that the CuO/FeO heterostructure ordered arrays are promising candidates for high-performance HS gas sensors that function at low temperatures as well as breath analysis systems for disease diagnosis.