Low temperature sputtered TiO2 nano sheaths on electrospun PES fibers as high porosity photoactive material

Abstract

We propose a low temperature approach based on combining an electrospinning methodology and reactive sputtering processes to realise a porous mesh of polyethersulfone (PES) fibers (∼700 nm in diameter) wrapped by TiO₂ nano-sheaths, active under UV illumination. The mesh has a porosity as high as ∼91% in volume and was prepared at T ≤ 160 °C. The effectiveness of the TiO₂/PES mesh under UV was proved by Methylene Blue (MB) dissociation experiments and related to the TiO₂ coverage properties, namely its thickness (∼15 nm), its nano-structuring (grains diameter 8–10 nm) and lattice structure (anatase) that improve the photo-activity action. The combination of electro-spinning plus sputtering processes lays the basis for high porosity and low cost, high throughput, high yield and flexible purifying filter technologies.