Fe_2O_3-loaded NiO nanosheets for fast response/recovery and high response gas sensor

摘要

Highlights•Fe2O3-loaded NiO nanosheets possess relatively large BET surface area.•The gas sensor based on 1.5% Fe2O3-loaded NiO nanosheets exhibits relatively high response of 170.7 and 107.9 with response/recovery time of 0.5/14.6s and 0.1s/11.4s to 100ppm ethanol and methanol at 255°C, respectively.AbstractPorous Fe2O3-loaded NiO nanosheets were obtained by the thermal decomposition nanosheets of iron element-loaded Ni(OH)2synthesized via microwave-assisted liquid-phase synthesis under atmospheric condition. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopic (TEM) and Brunauer Emmett Teller (BET) N2adsorption–desorption analysis were used to characterize the as-prepared products. Gas sensing measurement indicated that the sensor based on the 1.5% Fe2O3-loaded NiO nanosheets exhibits untrafast response speed as well as short recovery time and high responses to ethanol and methanol (the response/recovery time of the gas sensor are 0.5/14.6s and 0.1/11.4s with the responses of 170.7 and 107.9–100ppm ethanol and methanol, respectively). In addition, the 1.5% Fe2O3-loaded NiO nanosheets-based sensor can detect ethanol and methanol at a detection limit of well below 200ppb (the responses are 6.88 and 6.82–200ppb ethanol and methanol, respectively). The enhanced sensing behaviors can be attributed to the nanosheet-like structure and n-type Fe2O3/p-type NiO heterojunction. The time-saving method developed by us is easy to control to produce the nano-particulate composites without high experimental requirement and make it possible in commercial applications. Our work may explore a possibility to synthesize nanomaterial with ultrafast responding and fast recovering behaviors for real-time monitoring gas sensor.