Tailoring the energy level of Co3O4 by heteroatoms implantation for high-performance xylene detection

Xylene is a carcinogen, and long-term exposure to airborne content containing xylene can cause damage to humans and pose a carcinogenic risk. Therefore, it is necessary to develop sensors that can efficiently detect xylene. Co3O4 is a promising semiconductor sensing material for detecting xylene. However, pure Co3O4 sensors still face issues such as insufficient sensitivity, slow response and recovery times, and inadequate detection limits when detecting xylene. In this work, we introduced various heteroatoms into Co3O4 to regulate its xylene sensing performance. Among these products, Fe-Co3O4 demonstrated the highest response (Rg/Ra approximate to 34.5) towards 100 ppm xylene with a low limit of detection (0.2 ppm) and good long-term reliability at 120 degrees C. The enhanced xylene sensing properties were attributed to the regulation of chemisorbed oxygen through the elevated Fermi level. This research not only provides a promising xylene sensing material but also further confirms the Fermi level as a reliable reference for screening gas sensing materials.