A fast responsive and highly reproducible liquefied petroleum gas (LPG) detection of Cu_xZn_1-xSb₂O₆ (x = 0, 0.2, 0.4, 0.6, and 0.8) nanostructures

A repeatable and fast responsive room temperature (25 °C) liquefied petroleum gas sensor has been demonstrated. Catalytic additives comprising Cu_xZn_1-xSb₂O₆ (x = 0, 0.2, 0.4, 0.6, and 0.8) nanostructures were synthesised by the sol–gel technique for the first time. Spin-coated thin films were tested for liquefied petroleum gas detection at 25 °C. For analysing the obtained LPG sensing data, the as-synthesised materials were characterised using several relevant methodologies. The materials micro-structural characteristics were examined by scanning electron microscopy and X-ray diffraction. Vibrational modes were analysed using Fourier transform infrared (FTIR) spectroscopy. Optical characterisation was conducted using ultraviolet–visible (UV–Vis) spectroscopy. Among all the compositions of the synthesised Cu_xZn_1-xSb₂O₆ (x = 0, 0.2, 0.4, 0.6, and 0.8) nanostructures, the Cu_0.8Zn_0.2Sb₂O₆ thin film sensor exhibited the lowest resistance, owing to the optimal catalytic additive effect of copper, which include structural and chemical modifications. Even at ambient temperature, the Cu_0.8Zn_0.2Sb₂O₆ thin film sensor responded well to lower explosive limit (LEL) of LPG which is attributed to optimised copper doping. The process by which catalytic inclusion boost the LPG sensing characteristics was also established. Long-term analysis of sensing characteristics up to 90 days revealed the consistency and reliability of fabricated sensor.