Interfacial synthesis of polyaniline–polypyrrole on electrospun vanadium oxide-embedded TiO2 nanofibers with enhanced photocatalytic performance

Designing high-performance TiO2-based photocatalysts with a reduced bandgap is obligatory for utilizing abundant sunlight. In this study, a novel hybrid was fabricated by interfacial polymerization of polyaniline (PANi) and polypyrrole (PPy) on electrospun vanadium oxide (VOx)-embedded TiO2 nanofibers. The resulting TiO2–VOx/PANi–PPy hybrid was systematically characterized and used as the peroxymonosulfate activator for photocatalytic removal of Rhodamine B (RhB). The TiO2–VOx/PANi–PPy hybrid shows a reduced bandgap (2.14 eV) and improved photocatalytic performance as compared to TiO2–VOx/PANi (2.64), TiO2–VOx/PPy (2.58), and TiO2–VOx (2.96 eV). The influence of reaction parameters on photocatalytic performance was investigated, the reactive oxygen species were identified, and the photocatalytic mechanism was proposed which reveals the role of singlet oxygen and sulfate and hydroxyl radicals in RhB removal. Our study suggests a useful strategy for more efficient utilization of visible light in photocatalytic removal of organic pollutants.