Synergistic effect of NiFe2O4 and MWCNTs for ppb-level acetone detection at 150 oC

Acetone is a biomarker used in illness diagnosis and can lead to health issues. Chemiresistive sensors for acetone detection have been made using metal oxides, however they still require improvement in terms of sensitivity and operating temperature. In this study, we use a simple hydrothermal technique under surfactantless condition without subsequent high-temperature calcination treatment, which is more environment-friendly, energy-saving, to produce a variety of NiFe₂O₄/multi-walled carbon nanotubes (MWCNTs) composites with varying MWCNT contents for the detection of acetone. The findings demonstrate that the NiFe₂O₄ /MWCNTs composite-based chemiresistive gas sensor possesses a strong performance of 53.4 (The ratio of the resistance of the sensor in acetone atmosphere to that of the sensor in air) to 100 ppm acetone at 150 ^oC, while a ppb-level detection limit (102 ppb), wide detection range and good sensitivity are achieved at 150 ^oC. The synergistic impact of MWCNTs and NiFe₂O₄, as well as the high porosity and large specific surface area of the composite contribute to the composite-based sensor's better sensing capability. Our findings suggest that the binary metal oxide (metal oxide containing two types of metallic elements) /carbon material composite might be useful in the development of stable and sensitive acetone sensors for application in both industry and healthcare.