Silicalite-1/glass fibre substrates for enhancing the photocatalytic activity of TiO2

Abstract

Silicalite-1 (S1) coatings were prepared on silica wool substrates by hydrothermal synthesis and subsequently immersed into a Ti-containing sol at a steady rate of 30 cm min⁻¹. The material was annealed in a furnace at 90 °C for 2 h and 550 °C for 2 h to create a silica fibre core surrounded by concentric layers of silicalite-1 and TiO₂. The resulting samples were characterised by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) surface area measurement. The photocatalytic activity of the samples was evaluated using the intelligent ink test and during degradation of stearic acid under UVA light (λ = 365 nm). The new coated-fibres were shown to be substantially better photocatalysts than comparable TiO₂ coatings on plain glass fibres. The TiO₂/S1/glass fibres have potential use in air/water cleaning applications.