Black Phosphorus Nanosheets Decorated Multiscale Zinc Ferrite Spheres Toward Swift and Humidity-Tolerant Breath Acetone Sensing

Unreasonable acetone emission from various cosmetic and industrial products readily imposes severe ecological harm and human health through airborne transmission and groundwater circulation, thus necessitating the pressing requirement of sensitive and swift acetone detection. To this end, chemoresistive MEMS acetone sensors featuring the sensing layer of a few black phosphorus (BP) nanosheets-modified multiscale zinc ferrite (ZnFe2O4) spheres were leveraged in this work. After the optimization of constituent combination and operation temperature, the 0.5 wt% BP/ZnFe2O4 sensors could recognize 0.1–2 ppm acetone at 188 °C. With respect to pure ZnFe2O4 analog, the 0.5 wt% BP/ZnFe2O4 sensors delivered approximately twofold response enhancement (5.34 versus 2.73 toward 0.5-ppm acetone) and stronger sensitivity (5/ppm versus 3/ppm). Also, excellent selectivity, repeatability, and long-term stability were exhibited. The response/recovery times of 6/63 s toward 0.5-ppm acetone manifested a swift balance of gas–solid interaction. Inspiringly, the sensor showed an excellent humidity-resistant response toward 100-ppb acetone. Moreover, the simulated detection revealed a high application potential in diabetic monitoring featuring sub-ppm acetone and a high moisture environment. The ameliorated sensor performance after incorporating few but modest BP could be attributed to the consequent larger specific surface area, richer oxygen vacancies, and numerous p-n heterojunctions.