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.