Robust self-cleaning effects of cotton fabrics coated with reduced graphene oxide (RGO)-titanium dioxide (TiO ₂ ) nanocomposites

The self-cleaning textiles coated with reduced graphene oxide-titanium dioxide (TiO ₂ ) nanocomposites have enhanced photocatalytic activities and could have great potential in practical applications. However, it is still problematic regarding how to avoid aggregation of reduced graphene oxide nanosheets in producing reduced graphene oxide-TiO ₂ nanocomposites. In this research article, we propose a new method to reduce the aggregation of reduced graphene oxide nanosheets in producing cotton fabrics coated with reduced graphene oxide-TiO ₂ nanocomposites by combining vibration-assisted ball milling and hydrothermal synthesis process. The microstructure and photocatalytic-related properties of the resultant reduced graphene oxide-TiO ₂ nanocomposites and their coating cotton fabrics were characterized by using a series of techniques including field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray diffraction spectroscopy (XRD), Raman, particle size distribution, Brunauer-Emmett-Teller,(BET), transmission electron microscope (TEM), X-ray photoelectron spectrometer (XPS), diffuse reflectance spectra (DRS), ultraviolet photoelectron spectroscope (UPS), and photoluminescence (PL). It was indicated that the aggregation of reduced graphene oxide nanosheets in reduced graphene oxide-TiO ₂ nanocomposites was successfully avoided via ball milling in the presence of tetrabutyl titanate. After hydrothermal treatment, the resulting reduced graphene oxide-TiO ₂ nanocomposites were firmly immobilized on cotton fabric. It was demonstrated in the self-cleaning experiments that the resultant self-cleaning cotton fabrics are hydrophilic and could directly decompose color contaminants such as methylene blue, Congo red, and coffee stains under simulated sunlight irradiation due to the photo-degradation reactions of the reduced graphene oxide-TiO ₂ nanocomposite coating. The reduced graphene oxide-TiO ₂ nanocomposite-modified cotton fabric also exhibited excellent performance in both robust abrasion resistance and soap-washing resistance. The fabric photocatalytic self-cleaning capability was not found to decrease significantly after being repeatedly used for five times.