A quick-responsive gas sensor based on Co0.5Zn0.5Sb2O6 thin films for the detection of LPG levels below the lower explosive limit at room temperature†

Abstract

The present study has successfully developed a highly efficient LPG sensor functioning at ambient temperature, utilizing nanostructured cobalt–zinc antimonate (Co_0.5Zn_0.5Sb₂O₆). The fabricated film sensor has shown a rapid response to LPG concentrations below the lower explosive limit (LEL) under ambient conditions. A sol–gel method has been employed to synthesize Co_0.5Zn_0.5Sb₂O₆, enabling precise control over particle size and surface structure to enhance its sensing capabilities. X-ray diffraction (XRD) has confirmed its highly crystalline monoclinic structure with a Cc space group and refined lattice parameters of a = 6.6825(8)A°, b = 10.771(1)A°, c = 15.204(1) and β = 107.106(5)°. Fourier-transform infrared (FT-IR) spectroscopy has verified the presence of key functional groups, while scanning electron microscopy (SEM) has revealed its detailed surface morphology. The crystallite size of Co_0.5Zn_0.5Sb₂O₆ has been calculated approximately 43 nm. The sensor achieved a sensitivity of 2.85, particularly at an LPG concentration of 2000 ppm, which is below the LEL. Additionally, it demonstrated response and recovery times of approximately 30 and 140 seconds, respectively. These experimental outcomes have established that Co_0.5Zn_0.5Sb₂O₆ effectively detects LPG leaks below critical safety thresholds. These findings highlight its potential as a reliable and economical LPG detection in both domestic and industrial environments.