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

Defect and facet engineering arethe two effective approachestotune the surface reactivity of metal-oxide-based sensing materials.Here, oxygen vacancies defective of WO3 nanosheets withexposed (002) crystal facet [D-WO3-(002)] were obtainedby a simple hydrothermal-hydrogenation process. The resultsrevealed that a D-WO3-(002)-based acetone sensor exhibitsexcellent comprehensive gas sensitive performance: low limit of detection(0.5 ppm), wide range of 0.5-100 ppm (S =2.8 & SIM;45.6), high selectivity, fast response-recovery,and excellent repeatability. The outstanding gas-sensing performanceis attributed to the synergistic effects of the dominant (002) facetand the defect of oxygen vacancy structure, which effectively improvedthe surface reactivity of monoclinic WO3 nanosheets. Forhighly sensitive and wide range sensing performance, this work demonstratestremendous potential application prospect for environmental monitoringof acetone and non-invasive diagnosis of diabetes.