Photocatalytic effects of wool fibers modified with solely TiO2 nanoparticles and N-doped TiO2 nanoparticles by using hydrothermal method

Abstract

Abstract:The surfaces of wool fibers are modified with N-doped TiO2 nanoparticles by treating the fibers with tetrabutyl titanate and ammonium chloride under low temperature hydrothermal conditions to obtain wool fibers with photocatalytic functions in the visible light spectrum. The effects of nitrogen and sulfur in amino acids in keratin on the photocatalytic activity of TiO2 particle coated wool fibers are investigated. Changes of various fiber properties such as tensile strength, surface friction, photocatalytic activity, and self-cleaning performance of untreated, TiO2-coated and N-doped TiO2-coated wool fibers are studied. It is found that N-doped anatase TiO2 nanoparticles with an average grain size of 11.2 nm are synthesized and simultaneously grafted onto the wool fibers. After treatments, the crystallization index of the wool fibers is slightly reduced. The capability to protect against ultraviolet radiation is much enhanced. The performances of photocatalytic degradation of methylene blue dye and self-cleaning of red wine under both UV and visible light irradiation are endowed. It is also found that wool fibers coated with TiO2 particles without being doped by nitrogen still have apparent photocatalytic reactions and self-cleaning effects under visible light irradiation due to the formation of C-Ti 3+ , O-Ti 3+ , and N-Ti 3+ bonds between TiO2 and wool keratin on the wool fiber surfaces. Thus wool fabrics might not need to be coated with N-doped TiO2 nanoparticles to realize its self-cleaning effect under visible light. Such important conclusions would provide wool materials with wide applications in clothing and 3 technical products such as wastewater treatment.

Heterogeneous photocatalytic degradation of toluene in static environment employing thin films of nitrogen-doped nano-titanium dioxide

“…In the past few decades, considerable research studies have shown that doping TiO 2 with non-metal elements, such as carbon, boron, fluorine, nitrogen and sulphur, enables the realization of visible light-responsive TiO 2 . Among those studies, nitrogen doping has been proved to be a modest and most effective technique [15] to achieve visible light stimulated photocatalytic activities of TiO 2 . However, most of the studies on nitrogen-doped TiO 2 have assumed that the nitrogen doping results in a surface or sub-surface modification making it difficult to narrow down the band gap in the bulk of TiO 2 .…”

Immobilization of Titanium(IV) Oxide onto 3D Spongin Scaffolds of Marine Sponge Origin According to Extreme Biomimetics Principles for Removal of C.I. Basic Blue 9

“…The results obtained in this study motivated us to carry out experiments with other metal oxides such as titanium oxide. A study of the synthesis of titania in the presence of spongin-based scaffolds has not been reported before, but the immobilization of titania nanoparticles onto alternative proteinaceous substrates (e.g., wool or feather keratin) has been extensively studied [26,27,28].…”

Photostability of TiO2-Coated Wool Fibers Exposed to Ultraviolet B, Ultraviolet A, and Visible Light Irradiation

“…The optical absorption edge extends to visible light region owing to the coating of TiO 2 nanoparticles. It has been confi rmed that the co-doping of carbon, nitrogen, oxygen, and sulfur in the TiO 2 -modifi ed wool fi bers acts as a trapping center for electrons and holes, thereby reducing the recombination rate of charge carriers [49]. The relationship between (αhν) 2 and incident photon energy (hν) for the W2 specimens is shown in Figure 5, where α is the absorption coeffi cient.…”