K_xWO is a Novel Ferroelectric Nanomaterial for Application as a Room Temperature Acetone Sensor

A newly synthesized nanomaterial known as K_xW₇O₂₂ (K_xWO) exhibits a stable room-temperature ferroelectric property. This unique ferroelectric property has revealed that K_xWO is a promising material for application in a breath sensor, which can be used for patients to monitor their daily health condition and diagnose disease at every early stage with low cost, convenience, and non-invasion. In this study, we successfully synthesized nano-structured K_xWO through a low cost but high yield hydrothermal method. The sensing response of K_xWO to acetone is examined based on a chemiresistive effect. For the first time, we systematically studied how material structures and the component, potassium (K), can affect K_xWO-based sensing performance. The results indicate that the low temperature ferroelectric property of K_xWO causes an excellent response to acetone, which is the biomarker for diabetes. The lowest detection limit can be down to 0.1 ppm and the K_xWO-based sensor can operate at room temperature. In addition, the K_x component K_xWO and its crystal structure also play an important role in improving its sensing performance. Our results provide advanced research in (1) exploring the study of K_xWO material properties by tailoring the concentration of the potassium in K_xWO and introducing the surfactant Pluronic L-121 in the growing process, and (2) optimizing K_xWO sensing performance by controlling its material properties.