Enhanced Oxygen Vacancy Formation in Pt-WO3 via W–OH Bond Cleavage Using Water-Based One-Step Electrospinning for High-Performance Gas Sensors

Oxygen vacancies play a crucial role in charge transport and surface states in semiconductor metal oxides, significantly influencing various research fields, such as photocatalysis and gas sensor. Developing effective strategies to generate oxygen vacancies and thereby enhance device performance is highly desirable. In this study, we proposed a water-based one-step electrospinning method to introduce hydroxyl groups, leading to the synthesis of Pt-decorated WO3 nanofibers (Pt-WO3(H2O)) with increased oxygen vacancies. Density functional theory calculations revealed that the dissociation energy of W-OH is lower than that of the W-O bonds, promoting the formation of oxygen vacancies via W-OH bond cleavage. These vacancies reduced the adsorption energy of acetone on the WO3 surface, enhancing surface interactions. Consequently, the Pt-WO3(H2O) sensor exhibited an ultrahigh response of 82 to 1.8 ppm acetone at 300 °C, which was about 1 order of magnitude higher than the one fabricated by conventional electrospinning. These findings indicate that water-based electrospinning is an effective technique for generating oxygen vacancies in metal oxide nanofibers. Our high-performance acetone sensor, capable of detecting low concentrations, holds great potential for applications in noninvasive health screening.