Hydrothermal–Ultrasonication Synthesis of NiFe2O4 Nanospheres for Temperature-Controlled Xylene Gas Sensor

The present study covers nickel ferrite (NiFe₂O₄) as an efficient material for sensing of xylene gas. Blend technique (hydrothermal and ultrasonication) was adopted for the fabrication of NiFe₂O₄ nanospheres due to control over temperature, pressure, and acoustic waves. NiFe₂O₄ were discovered to be very specific for the detection of xylene gas. The surface, functional group, size, and stability with optical properties of NiFe₂O₄ nanospheres were examined using various techniques (XRD, FT-IR, XPS, BET, FESEM, and EDS). After being subjected to a variety of gases (acetone gas, ammonia, benzene, LPG, chlorine, and carbon monoxide), the NiFe₂O₄ nanospheres were found to be very specific for the detection of xylene. The sensing of xylene for 70 ppm was perform at different temperature ranges (25, 50, 75, 100, and 150 °C). Maximal response at 68.5% was observed at 29.3 and 36.5 s of response and recovery time for xylene at 70 ppm. 70 days of reproducibility was noted for NiFe₂O₄. Xylene gas was found to be reactive with the surface of NiFe₂O₄ nanospheres. Specificity toward xylene gas involves numerous factors such as improved magnetic characteristics, surface charge, particle size, operating conditions, and enhanced electronic properties.