Preparation of Flower-Like Cu-WO3 Nanostructures and Their Acetone Gas Sensing Performance

Urchin-like Cu-W18O49 and flower-like Cu-WO3 structures were successfully synthesized using a hydrothermal process followed by calcination. The synthesized products were characterized using XRD, SEM, and TEM. The results revealed that the as-prepared urchin-like and flower-like samples with monoclinic structures, which were approximately 1 μm and 1-2 μm, respectively, possessed microflower architecture assembled by the nanosheet. In addition, the gas sensing properties of monoclinic-structured Cu-WO3 to acetone were measured using a static state gas sensing test system. The sensor based on the flower-like Cu-WO3 nanostructures, which were calcined at 600°C, exhibited high sensitivity toward 10 ppm acetone at an optimum temperature of 110°C, and the maximum sensitivity reached 40, which was approximately four times higher than that of urchin-like WO3 that was annealed at 300°C. The sensitivity was improved by increasing the acetone concentration. The detection limit was as low as 1 ppm. Using linear fit, the sensor was determined to be sufficiently sensitive to detect acetone in a detection range of 1 to 10 ppm even in the presence of interfering gases, which suggests that this type of sensor has excellent selectivity and has the potential for use in acetone gas sensors in the future.