Designing of LaCrO3 − TiO2 nanocomposites p: n heterojunction-based sensor material for the selective detection of volatile petrol vapors (PV) and CO2 gas vapors

In the present research TiO2 modified LaCrO3 nanostructure has been designed by simple sol-gel method. The thick films of TiO2 with different concentrations with LaCrO3 were fabricated by using screen printing methodology. In present study, the structural properties of TiO2 doped LaCrO3 were confirm by using X-ray diffractometer (XRD). While the morphological properties and surface characteristics of fabricated material analyzed using scanning electron microscopy (SEM). The energy dispersive spectroscopy (EDS) was utilized for chemical composition of the prepared material. Transmission electron microscopy (TEM) confirms the orthorhombic crystal lattice structure and morphology of Ti-doped LaCrO3. While, Fourier transform infrared (FT-IR) spectroscopy was used to investigate the M − O bonding vibrational stretching frequencies of LaCrO3 and TiO2 materials. The zeta potential was recorded for stability of all Ti doped LaCrO3 nanostructures. The Brunauer-Emmett-Teller (BET) was analyzed for surface area and pore diameter parameters of the fabricated materials. The fabricated materials were checked for application as a sensor for different pollutant gases like Ethanol, CO2, NO2, and petrol vapors. The sensor demonstrates the sensitivity for petrol vapors at 150°C for 0.3 M% TiO2 doped LaCrO3. And exceptionally 0.5 M% TiO2 doped LaCrO3 sensor showed better response for CO2. The reproducibility confirms the stability of 0.3 M % TiO2 doped LaCrO3 sensor and 0.5 M % TiO2 doped LaCrO3 sensor. The rapid response and recovery were recorded for both the sensors viz. 0.3 M % and 0.5 M % TiO2 doped LaCrO3. Schematic of TiO2 doped LaCrO3 sensor with various concentrations. [Display omitted] •Sol-gel synthesis of TiO2 modified LaCrO3 by citrate method.•LaCrO3:TiO2 heterojunction nanocomposite thick films preparation by screen printing strategy.•The TiO2 concentrations from 0.1 M %, to 0.7 M % investigated for gas sensing study.•Excellent gas response and selectivity for 0.3 M % TiO2 – LaCrO3 sensor for PV.•Rapid response and recovery for 0.3 M % TiO2 –LaCrO3 sensor for PV.