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Dye sensitization represents a promising route to address the limited photoabsorption in semiconductor photocatalysis. However, efficient water purification using dye-sensitized photocatalysts has remained an unmet challenge. Here we report a novel strategy to promote dye-sensitized photocatalysis by combining the advantages of interfacial Fenton reaction construction and air-liquid-solid triphase contact. An alveoli-like Janus membrane was developed with bilayer electrospun micro/nanofibers, where the outer layer is hydrophilic semiconductor catalyst sensitized by an iron (II) phthalocyanine (FePc) photosensitizer, which can also act as the trigger of H2O2 activation; the hydrophobic internal layer serves as a gas passage to deliver O2 from air to the catalytic interface, boosting the photoinduced electrons conversion and H2O2 generation. This architecture allows a superior level of photosensitizer decoration when using TiO2 as the model semiconductor catalyst, which corresponds to highly efficient activity for photodegradation of organic contaminations accompanied with a high apparent quantum yield at around 660 nm. Our work may provide new insights into the development of high-efficiency solar driven photocatalysts for widespread applications.

TiO2 holds great promising for addressing the environmental issues via solar-to-chemical energy conversion. However, the large-scale application is greatly limited by its poor optical response (below 400 nm). In this study, we have successfully synthesized a visible light driven TiO2 catalyst via a facile hydrothermal route by using amidoximated polyacrylonitrile (PAN) fiber as the support for the first time. The fibrous bidentate ligands not only facilitated the visible light harvesting of TiO2 through ligand-to-metal charge transfer (LMCT) sensitization but also realized the incorporation of N atoms into the TiO2 lattice during the preparation. Such a unique architecture endows the TiO2 with high photocatalytic activity for degradation of several emerging organic contaminations under visible light irradiation (λ > 420 nm), which is dictated by both LMCT and N-doping mechanism. Furthermore, the fibrous support shows high resistance to active oxidizing species and imparts the as-prepared catalyst with excellent cycling stability, demonstrating the robustness of the constructed photocatalytic system for long-term applications. Our findings may offer a new strategy for designing promising visible-light-driven photocatalysts for environmental remediation.