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

We propose an approach based on combining electrospun methodology and reactive sputtering processes to realise a porous mesh of polyethersulfone (PES) fibers wrapped by TiO2 layers, active under UV illumination. The mesh has a porosity as high as ?91% in volume and was prepared with a thermal budget lower than 180°C. The activity 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 (?15nm) and lattice structure (anatase) that improve the photo-activity actions with reduced electron-hole recombination. Anatase formation under 180°C is an unexpected result and here attributed to the specific sputtering conditions. The combination of electro-spinning plus sputtering processes poses the basis for high porosity and low cost, high throughput, high yield and flexible purifying filter technologies.