H₂S detection at low temperatures by Cu₂O/Fe₂O₃ heterostructure ordered array sensors

2D heterostructures are promising gas sensor materials due to their surface/interface effects and hybrid properties. In this research, Cu₂O/Fe₂O₃ heterostructure ordered arrays were synthesized using an in situ electrodeposition method for H₂S 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 Cu₂O/Fe₂O₃ heterostructure ordered arrays exhibits a dramatic improvement in H₂S 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 H₂S atmosphere. These good performances are also attributed to the formation of metallic Cu₂S conducting channels. Our results imply that the Cu₂O/Fe₂O₃ heterostructure ordered arrays are promising candidates for high-performance H₂S gas sensors that function at low temperatures as well as breath analysis systems for disease diagnosis.