Polyoxometalate Cluster-Guided Dynamic Nucleation and Hierarchical Growth of Branched WO₃ Nanofibers with Ultrafine Pt Nanoparticles for Advanced Gas Sensing

In the food industry, 2,3-butanedione is a significant volatile organic compound valued for its unique aroma and flavor. Real-time detection of its concentration during food preparation is crucial for ensuring optimal taste and food safety. However, accurately detecting low concentrations of 2,3-butanedione requires highly sensitive sensing materials. Herein, we present a novel synthesis of branched WO₃ nanofibers decorated with ultrafine Pt nanoparticles (Pt NPs-WO₃ NFs), templated by polyoxometalate (POM) clusters, through a combination of electrospinning and thermal oxidation strategies for advanced gas sensing applications. This Pt NPs-WO₃ NFs-based sensor exhibits impressive sensitivity (<i>R</i>_a/<i>R</i>_g = 2.25 vs 500 ppb), a low detection limit of 10 ppb, high selectivity, excellent repeatability, and stable performance over a period of 25 days. Using POM clusters as templates offers significant advantages over the traditional WCl₆ salt in synthesizing WO₃ NFs with smooth surfaces. Specifically, the POM clusters guide the dynamic nucleation and hierarchical growth of branched NFs, enhancing the concentration of oxygen vacancies and increasing the number of active adsorption sites. Furthermore, the uniform dispersion of ultrafine Pt NPs (≈ 4 nm) within the WO₃ NFs further enhances the catalytic activation of 2,3-butanedione, significantly improving the gas sensing performance. This study introduces an efficient method to synthesize Pt NPs-WO₃ NFs with potential for manufacturing advanced nanostructured sensing materials using POM clusters as templates, paving the way for high-performance gas sensing technologies.