Synthesis and characterization of zirconium (IV) and vanadium (III) doped CeO2/TiO2 core/shell nanostructures as a gas sensor

The CeO2/TiO2 core/shell nanostructures were successfully synthesized by sol-gel assisted hydrothermal method and doped by Zr4+ and V3+ ions. Different characterization experiments used to identify particles morphology and microstructures to confirm the formation of desired core/shell structure. The produced materials were used to make gas sensors for volatile organic compounds. Doping the core/shell structure by 1% molar ratios of zirconium (IV) and vanadium (III) increased its sensitivity from 26.50 to 277.50 with respect to 420 ppm ethanol at room temperature (29 degrees C, 45 % RH). Linear dependence of the sensitivity logarithm to the concentration of volatile organic compounds with reasonably low relative standard deviation (%RSD) suggests that the sensors can be used for quantitative and qualitative measurements. Long time measurements of the sensitivity revealed that the sensors output are temporally stable up to 11 months. The sensitivity mechanism is explained based on the depletion region created in the hetero-junction of semiconductor materials. (C) 2020 Published by Elsevier B.V.