Defective WO₃ Nanosheets with (002)-Exposed Facet for Highly Sensitive Acetone Detection

Defect and facet engineering are the two effective approaches to tune the surface reactivity of metal-oxide-based sensing materials. Here, oxygen vacancies defective of WO3 nanosheets with exposed (002) crystal facet [D-WO3-(002)] were obtained by a simple hydrothermal–hydrogenation process. The results revealed that a D-WO3-(002)-based acetone sensor exhibits excellent comprehensive gas sensitive performance: low limit of detection (0.5 ppm), wide range of 0.5–100 ppm (S = 2.8∼45.6), high selectivity, fast response–recovery, and excellent repeatability. The outstanding gas-sensing performance is attributed to the synergistic effects of the dominant (002) facet and the defect of oxygen vacancy structure, which effectively improved the surface reactivity of monoclinic WO3 nanosheets. For highly sensitive and wide range sensing performance, this work demonstrates tremendous potential application prospect for environmental monitoring of acetone and non-invasive diagnosis of diabetes