Facile synthesis of LaNi1-xTixO3 nanoparticles and enhanced ethanol-sensing characteristics

Nanoparticles of LaNi1-xTixO3 (0 <= x <= 0.2) with perovskite structure were successfully synthesized by the sol-gel method. The thermal decomposition characteristics, crystal structure, chemical composition and morphology of the nanoparticles were investigated. The prepared LaNiO3 nanoparticles have a particle size distribution of 30-50 nm and a phase formation temperature of about 500 degrees C. The B-site Ti4+ doping can substitute Ni3+ in the crystal without changing the rhombohedral structure of LaNiO3, but causing lattice expansion. The gas sensors based on the LaNi1-xTixO3 nanoparticles heat-treated at 700 degrees C exhibit excellent responses to ethanol, showing nearly linear relationships for the ethanol concentration range of 100-500 ppm. The Ti doping at B-site can increase the number of electrons in the redox reaction and suppress grain growth, thus increasing the specific surface area of the material and contributing to the gas response. For an operation temperature of 300 degrees C, the LaNi0.8Ti0.2O3 nanoparticles display excellent ethanol-sensing performance, including good repeatability and prominent selectivity to ethanol vapor. The results suggest that LaNi1-xTixO3 nanoparticles are potential candidates for ethanol detection.