Screen Print Fabricated In3+ Decorated Perovskite Lanthanum Chromium Oxide (LaCrO3) Thick Film Sensors for Selective Detection of Volatile Petrol Vapors

The present work deals with the fabrication of undoped lanthanum chromium oxide and indium doped lanthanum chromium oxide material by cost effective sol–gel method. The four sensors were fabricated by screen printing technique. The indium ion concentration was varied for LaCrO 3 material from 0.1 M% to 0.7 M% to access the comparative gas sensing results. All the prepared materials were characterized by XRD, SEM, EDAX, TEM and IR to confirm their structural and chemical composition. The prepared sensors viz. 0.1 M% In 3+ doped LaCrO 3 , 0.3 M% In 3+ doped LaCrO 3 , 0.5 M% In 3+ doped LaCrO 3 and 0.7 M% In 3+ doped LaCrO 3 were investigated for gas sensing mechanism for selected gases such as petrol vapours, ethanol, ammonia, NO 2 , H2S and CO 2 gases. The optimum response was recorded for tested gases for all the prepared sensors. The 0.3 M% In 3+ doped LaCrO 3 found to be exceptional for petrol vapour and highest response was recorded for petrol vapors for 0.3 M% In 3+ doped LaCrO 3 thick film sensor. All the indium doped are found to be good sensors for petrol vapours and moderate for other tested gases. The prime parameters for the sensors such as selectivity, response and recovery and reproducibility were recorded for the prepared sensor. The response and recovery was very rapid for 0.3 M% In 3+ doped LaCrO 3 sensor. The gas sensing mechanism for petrol vapours has been established for 0.3 M% In 3+ doped LaCrO 3 sensor via hole accumulation layer mechanism. Graphic Abstract The Schematic abstract exhibits the synthesis of In-doped LaCrO 3 (0.1M%. 0.3M%, 0.5M% and 0.7M %) by the sol-gel manner. It also illustrates the characterization and optimal gas response to volatile petrol vapors among all the gases. Schematic of In 3+ -doped LaCrO 3 sensor with various concentrations