Sustainable and cost-effective functionalization of textile surfaces with Ag-doped TiO2/polysiloxane hybrid nanocomposite for UV protection, antibacterial and self-cleaning properties

• Improved photocatalytic activity of TiO 2 by Ag doping. • Co-operative synergism of polysiloxane backbone, TiO 2 , Ag and textile surface. • Semiconductor-metal-semiconductor heterojunction on the TiO 2 /polysiloxane/Ag/textile nanocomposite surface. • Outstanding multifunctional antibacterial, UV protective and self-cleaning properties of TiO 2 /polysiloxane/Ag/textile nanocomposite. • Excellent wash durability of the TiO 2 /polysiloxane/Ag/textile nanocomposite. In this work, TiO 2 was incorporated into the surface of cotton fabrics by an in situ sol–gel/hydrothermal approach. Dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (SiQAC) was added as a bio-barrier Si precursor to enhance the synergistic effect/binding of TiO 2 to the surface of cotton fabric. A small amount of silver nitrate (AgNO 3 ) was added to produce Ag-doped TiO 2 -coated fabric during hydrothermal treatment. The treated cotton fabric samples were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction spectroscopy (XRD) to determine the surface morphology, chemical composition, chemical bonding and crystal structure, respectively. These results confirmed the successful application of well-dispersed TiO 2 , Ag and SiQAC on the surface of cotton fabric. The cotton fabric functionalized with TiO 2 + SiQAC + Ag nanocomposite exhibited superior antibacterial activity against Escherichia coli and Staphylococcus aureus , very good UV protection and excellent self-cleaning performance, which were maintained even after repeated washings. The wash resistance of the newly developed TiO 2 -based hybrid nanocoating was attributed to the formation of the SiQAC polysiloxane matrix, which served as an anchoring site for the Ag-doped TiO 2 through the formation of Si–O–Ti bonds. The enhanced photocatalytic activity of TiO 2 in the coating was attributed to the formation of the Ag/AgCl/TiO 2 heterostructure, which is promising for the surface and interface engineering of TiO 2 -modified fabric.