Oxygen Vacancy Enabled Electronic Structure Engineering of Pt-WO₃ Nanosheets toward Highly Efficient BTEX Sensing

A Pt nanoparticle-immobilized WO₃ material is a promising candidate for catalytic reactions, and the surface and electronic structure can strongly affect the performance. However, the effect of the intrinsic oxygen vacancy of WO₃ on the d-band structure of Pt and the synergistic effect of Pt and the WO₃ matrix on reaction performance are still ambiguous, which greatly hinders the design of advanced materials. Herein, Pt-decorated WO₃ nanosheets with different electronic metal-support interactions are successfully prepared by finely tuning the oxygen vacancy structure of WO₃ nanosheets. Notably, Pt-modified WO₃ nanosheets annealed at 400 °C exhibit excellent benzene series (BTEX) sensing performance (S = 377.33, 365.21, 348.45, and 319.23 for 50 ppm ethylbenzene, benzene, toluene, and xylene, respectively, at 140 °C), fast response and recovery dynamics (10/7 s), excellent reliability (σ = 0.14), and sensing stability (φ = 0.08%). Detailed structural characterization and DFT results reveal that interfacial Pt^δ+-O_v-W⁵⁺ sites are recognized as the active sites, and the oxygen vacancies of the WO₃ matrix can significantly affect the d-band structure of Pt nanoparticles. Notably, Pt/WO₃-400 with improved surface oxygen mobility and medium electronic metal-support interaction facilitates the activation and desorption of BTEX, which contributes to the highly efficient BTEX sensing performance. Our work provides a new insight for the design of high-performance surface reaction materials for advanced applications.