Bullet-like ZnFe2O4 for acetone gas sensing application

This study reports the synthesis of a novel bullet-like ZnFe₂O₄ via a simple hydrothermal method followed by thermal treatment. The crystal structure and morphology of the synthesized ZnFe₂O₄ were characterized using various techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. For comparative purposes, ZnO was also produced employing the same synthesis method. The investigation revealed that the optimal working temperature for the gas sensor utilizing bullet-like ZnFe₂O₄ is 140 °C, which is 120 °C lower than that of the ZnO-based sensor (260 °C). At this optimal temperature, the ZnFe₂O₄ sensor exhibits favorable performance toward 100 ppm acetone, with a response value of 76.14, rapid response time (11 s) and recovery time (15 s), as well as good selectivity and stability. These results indicate that bullet-like ZnFe₂O₄ has potential for gas sensing applications, particularly for the selective detection of acetone gas in low-power devices, though its sensing performance may be further improved by structural modification or composite doping.