Black phosphorus nanosheets-sensitized Zn-doped α-Fe2O3 nanoclusters for trace acetone detection

Acetone vapor not only poses a significant threat to the ecological environment and human health but serves as a specific volatile organic compounds (VOCs) biomarker within the exhaled breath to distinguish individual diabetes, thereby urgently necessitating a sensitive and selective acetone detection. To this end, conductometric gas sensors featuring black phosphorus nanosheets (BP)-decorated Zn-doped hematite (α-Fe2O3) nanoclusters as the sensitive material were prepared. By subtly modulating the componential ratio and operation temperature, the optimal Zn-doped α-Fe2O3/BP sensor delivered a prominent response of 5.32 and short response/recovery times of 8/68 s toward 0.5 ppm acetone at 160 °C as well as a large sensitivity of 5.3/ppm over the concentration range of 0.1–1.5 ppm. Moreover, favorable selectivity, repeatability, and long-term stability were demonstrated. The superior sensing performance after incorporating a tiny but moderate amount of BP over Zn-doped α-Fe2O3 sensors could be attributed to the consequent enlarged specific surface area, increased oxygen vacancies, and numerous p-n heterojunctions. Furthermore, additional polylactic acid (PLA) encapsulation membrane endowed the as-prepared sensors with a remarkably improved humidity tolerance, showcasing a huge application potential in non-invasive diabetes diagnosis from exhaled breath featuring high-humidity conditions in the future.