Surface active site control of spinel-type CdIn2O4 gas sensor by hard template method and low calcination temperature strategy for Ppb-level 2-butanone sensing

Industrial waste gas is the main force of environmental pollution, and its monitoring and control are particularly important. As a kind of chemical material and solvent commonly applied in industry, production and emissions of 2-butanone have been rising steadily year by year. It is particularly important for the detection of this gaseous substances. Spinel metal oxides have great potential in the field of gas detection, but the high calcination temperature of their synthesis often leads to the decrease of metal active sites on the surface and the loss of oxygen vacancies, which are not conducive to gas sensing performance. In this research, a hydrothermal method was adopted to synthesize In 2 O 3 nanospheres as hard templates, and the crystal structure of berry-like CdIn 2 O 4 was prepared at a low calcination temperature. The surface was enriched with an active site In. Gas-sensitive tests show that the CdIn 2 O 4 –2 step-500-based sensor has a sensitivity of 148 to 100 ppm 2-butanone gas and shows a low LOD (125 ppb) at 160 °C. The method in this paper not only provides a way to enhance spinel metal oxidation detection of 2-butanone gas, but also the prepared sensor has great application prospects in industrial monitoring.