Highly dispersed g-C3N4 on one-dimensional W18O49/carbon nanofibers for constructing well-connected S-scheme heterojunctions with synchronous H2 evolution and pollutant degradation performance

Abstract

Synchronous dual-functional photocatalytic reaction can simultaneously consume photogenerated electrons and holes, leading to redox reaction, which is a promising photocatalytic reaction system model. However, the severe recombination of photogenerated charge carriers in photocatalysts limits their photocatalytic performance. In this work, W₁₈O₄₉/C@g-C₃N₄ S-scheme heterojunctions nanofibers with core-shell structure were prepared through electrospinning combined with the vapor deposition method, for high-performance synchronous photocatalytic H₂ evolution and pollutant degradation. The X-ray photoelectron spectroscopy and Mott-Schottky results demonstrated that the S-scheme heterojunctions effectively separate charges while maintaining high redox capacity. The UV-vis-NIR absorption spectra results revealed the LSPR effect in W₁₈O₄₉, which can generate “hot electrons”. The scanning electron microscope images showed that the unique core-shell structure independently consumes electrons and holes, thereby enhancing charge separation and accelerating carrier kinetics. Specifically, the synchronous H₂ evolution and RhB degradation efficiency of W₁₈O₄₉/C@g-C₃N₄ nanofibers were approximately 5.60 and 3.51 times higher than that of W₁₈O₄₉/C, and 2.45 and 22.55 times higher than that of C@g-C₃N₄ nanofibers, respectively. Furthermore, the ultra-long one-dimensional network structure of W₁₈O₄₉/C@g-C₃N₄ nanofibers enables easy recycling after liquid reactions. This study presents a novel approach for customizing band structures and unique surface morphology to improve synchronous dual-functional photocatalytic activity.