Oxygen vacancy-rich, Ru-doped In2O3 ultrathin nanosheets for efficient detection of xylene at low temperature

The oxidation capacity and the quantity of chemisorbed oxygen are known to determine the extent of reaction with a target gas and thus deeply affect the sensing properties of a material. Therefore, to improve the reaction extent and enhance the sensing performance of a sensing material, a feasible and effective route is to increase the amount of chemisorbed oxygen on its surface. In this work, Ru species were successfully doped into the lattice of ultrathin In2O3 nanosheets. As a result, the oxygen vacancy enriched Ru-doped In2O3 not only exhibits a great ability to absorb oxygen on the surface, but also exhibits excellent catalytic ability for the selective oxidation of xylene. The 0.5% Ru-In2O3 sensor shows the best sensing performance for xylene detection, including ultrahigh response (R-a/R-g = 128.9 to 100 ppm), superior selectivity, low operating temperature (120 degrees C) and low detection limit (0.1 ppm). The excellent sensing properties make Ru-doped In2O3 a promising sensing material for xylene detection. Finally, we reveal that benzoic acid is the main intermediate for this sensing reaction.