RESUMEN
It is well known that ultraviolet (UV) and blue light cause a series of health problems and damages to polymer materials. Therefore, there are increasing demands for UV-blue light-shielding. Herein, a new type of iron-doped titania (Fe-TiO2) nanoparticle was synthesized. Fe-TiO2 nanoparticles with small particle size (ca. 10 nm) are composed of anatase and brookite. The iron element is incorporated into the lattice of titania and forms a hematite phase (α-Fe2O3). The iron doping imparted full-band UV and blue light absorption to Fe-TiO2 nanoparticles, and greatly suppressed the photocatalytic activity. The prepared Fe-TiO2/polyurethane (PU) films exhibited prominent UV-blue light-shielding performance and high transparency, which showed great potential in light-shielding fields.
RESUMEN
Membrane-based technologies are attractive for remediating oily wastewater because they are relatively energy-efficient and are applicable to a wide range of industrial effluents. For complete treatment of oily wastewater, removing dissolved contaminants from the water phase is typically followed by adsorption onto an adsorbent, which complicates the process. Here, an in-air superhydrophilic and underwater superoleophobic membrane-based continuous separation of surfactant-stabilized oil-in-water emulsions and in situ decontamination of water by visible-light-driven photocatalytic degradation of dissolved organic contaminants is reported. The membrane is fabricated by utilizing a thermally sensitized stainless steel mesh coated with visible light absorbing iron-doped titania nanoparticles. Post annealing of the membrane can enhance the adhesion of nanoparticles to the membrane surface by formation of a bridge between them. An apparatus that enables continuous separation of surfactant-stabilized oil-in-water emulsion and in situ photocatalytic degradation of dissolved organic matter in the water-rich permeate upon irradiation of visible light on the membrane surface with greater than 99% photocatalytic degradation is developed. The membrane demonstrates the recovery of its intrinsic water-rich permeate flux upon continuous irradiation of light after being contaminated with oil. Finally, continuous oil-water separation and in situ water decontamination is demonstrated by photocatalytically degrading model toxins in water-rich permeate.
RESUMEN
Novel photocatalyst, poly(itaconic acid-co-2-acrylamido-2-methylpropane-1-sulfonic acid) iron doped titania/silane was successfully prepared by the polymerization of iron doped titania/silane and two functional monomers, itaconic acid and 2-acrylamido-2-methylpropane-1-sulfonic acid in aqueous solution using ethylene glycol dimethacrylate as cross-linker and benzoylperoxide as initiator. The sample was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Diffuse reflectance spectroscopy (DRS) techniques. Effects of various factors like pH, adsorbent dose, contact time, and ionic strength on the adsorption capacity of photocatalyst for Victoria blue (VB) were studied by batch adsorption experiments. The kinetic data were found to follow pseudo-second-order kinetic model with low chi square, χ(2) values and R(2) values closer to unity. The equilibrium data were in well agreement with Langmuir isotherm model and maximum adsorption capacity was found to be 153.89 mg/g. The swelling capacity of the adsorbent with changes in pH, time and temperature was also investigated. The kinetics of photocatalytic degradation of VB by the photocatalyst found to follow first-order kinetics. The regeneration and repeated use of photocatalyst were also examined upto four cycles. The prepared photocatalyst was found to be efficient photocatalyst-cum-adsorbent for the degradation of VB from aqueous solutions under solar light.