Controlling the growth of nanosized titania via polymer gelation for photocatalytic applications (original) (raw)
Advanced Powder Technology, 2014
In this study, polyacrylamide gel method was used for preparation of pure and mixed phase TiO 2 nanoparticles. The influence of synthesis conditions on the physicochemical properties of products was investigated. It was found that the type of acid, which was used for acidifying the precursor solution together with calcination temperature can affect the phase structure, crystalline size, morphology and thereby photocatalytic activity of obtained TiO 2 nanoparticles. Different trends were observed during the phase transformation, particle growth, shift in energy of band gap with the change in tensile strain to compressive strain of the prepared TiO 2 nanomaterial. X-ray diffraction (XRD) showed that prepared nanocrystals, which were calcined at 450 °C have pure anatase and anatase-rutile mixed structures. The prepared samples having crystallite size between 5 nm and 60 nm were observed at different calcination temperatures. In addition, the photocatalytic activities of the prepared samples were evaluated by monitoring the degradation of Cresol Red (CR). The results show that the photocatalyst (TEC I), exhibits the highest photocatalytic efficiency where 94.7% of CR can be decomposed after UV exposure for 75 min.
Sol-gel preparation of surfactants assisted Titania for solar photocatalysis
Focus on Surfactants, 2020
A typical sol-gel process with little modifications was developed to enhance the sun light photo catalysis. The synthesis of sodium influenced TiO 2 particles was done using surfactants like Cetyl Trimethyl Ammonium Bromide (CTAB), Polyvinyl Pyrrolidone (PVP) and Sodium Dodecyl Sulfate (SDS) to obtain better surface morphology by sol-gel process with surfactant assisted templating mechanism. X-ray patterns show the formation of anatase TiO 2. Methylene Blue (MB) was used as a model dye for photo catalytic degradation with various surfactant assisted titania nano particles in solar irradiation.
Journal of Physical Chemistry C, 2008
Mixed-phase nanocrystalline titania (TiO 2 ) with varying rutile content has been synthesized via solvent mixing and calcination (SMC) treatment of sol-gel-derived nanocrystalline anatase-TiO 2 and rutile-TiO 2 precursors. The mixed-phase nanocrystalline TiO 2 processed via sol-gel SMC has been characterized using X-ray diffraction, the scanning electron microscope, high-resolution transmission electron microscope, and ultraviolet-visible (UV-vis) diffuse reflectance spectroscope for analyzing its morphology, phase contents, nanocrystallite size distribution, and band gap. The photocatalytic activity of mixed-phase nanocrystalline TiO 2 processed via sol-gel SMC is measured by monitoring the degradation of the methylene blue dye in an aqueous solution, under the UV-radiation exposure, using the UV-vis absorption spectroscope. It is demonstrated that the photocatalytic activity of mixedphase nanocrystalline TiO 2 processed via sol-gel SMC is a function of rutile content with the maximum photocatalytic activity observed for 40 wt% rutile. Thus, the synergistic effect has been observed between anatase-TiO 2 and rutile-TiO 2 , which has been satisfactorily explained using a new model based on the band-gap variation in the connected nanocrystallites as a function of the size distribution and the phases involved, which overcomes the limitations of the existing models proposed earlier in the literature.
Titania Nanoparticles Synthesized by Sol-Gel Technique
Abstract: Titania (TiO2) nanoparticles were prepared by combining bulk titania with trisodium citrate solution at room temperature without calcination. The formation of titania nanoparticles was confirmed from XRD and by the dominant FTIR peaks at 621 cm-1, 412 cm-1. UV-Visible analysis shows the occurrence of strong red shift, confirming the presence of nanoparticles which is essential for higher photo catalytic activities. TGA analysis reveals that the synthesized titania nanoparticles were thermally stable up to 700 °C. SEM image shows that the particles of the synthesized sample are in nanometer range which is in accordance with UV-Visible studies.
Catalysts
Titania photocatalysts have been intensively examined for both mechanism study and possible commercial applications for more than 30 years. Although various reports have already been published on titania, including comprehensive review papers, the morphology-governed activity, especially for novel nanostructures, has not been reviewed recently. Therefore, this paper presents novel, attractive, and prospective titania photocatalysts, including zero-, one-, two-, and three-dimensional titania structures. The 1D, 2D, and 3D titania structures have been mainly designed for possible applications, e.g., (i) continuous use without the necessity of particulate titania separation, (ii) efficient light harvesting (e.g., inverse opals), (iii) enhanced activity (fast charge carriers’ separation, e.g., 1D nanoplates and 2D nanotubes). It should be pointed out that these structures might be also useful for mechanism investigation, e.g., (i) 3D titania aerogels with gold either incorporated inside...
Preparation of titania nanotape array and its photocatalytic property
Journal of Physics and Chemistry of Solids, 2008
A TiO 2 nanotape array was fabricated by a seed-induced hydrothermal method without using any template. The TiO 2 nanotape with an average width of about 60 nm was grown as a columnar structure with a height of 7 mm on Ti substrate. It was highly porous and robust structure due to the formation of 3D-network among the individual nanotapes. No sodium contamination was found in this TiO 2 within the detection level of the energy-dispersive X-ray (EDX) analysis. The X-ray diffraction (XRD) patterns indicate that the TiO 2 nanotape array is highly crystallized anatase phase. The fabricated TiO 2 nanotape array demonstrated a high photocatalytic activity: its activity was 1.41 times that of the commercial Degussa P25 in evolving CO 2 from the decomposition of gaseous 2-propanol.
Topics in Catalysis, 2010
Mesoscopic crystalline anatase particles of titanium(IV) oxide (titania) with decahedral morphology and with octahedral morphology were synthesized by gas-phase reaction of titanium(IV) chloride with oxygen and hydrothermal reaction of titanate nanowires in an alkaline medium, respectively, and their photocatalytic activities in relation with their crystal morphology were investigated.
Titania based nanocomposites as a photocatalyst: A review
AIMS Materials Science, 2016
Titanium dioxide or Titania is a semiconductor compound having remarkable dielectric, electronic and physico-chemical surface properties. It has excellent photocatalytic efficiency in presence of UV light. The curious grey matter of scientists has forced them to focus their attention to make Titania capable of utilizing the whole visible spectrum of light also. The hurdle that they faced was larger band gap of 3 eV and more, for this, efforts were directed towards adding other materials to Titania. The present article reviews the recent advances in the synthesis of different Titaniumbased nanocomposite materials and their photocatalytic efficiency so as to apply them for several applications such as removal of dyes, other water pollutants, microbes and metals. A brief explanation of the photocatalytic process and the structural properties of TiO 2 are also touched upon. Various past and recent approaches made in these directions of utilizing Titania based nanocomposites for photocatalytic activities are reviewed. It is suggested that there is a need to establish the kinetics of photo-corrosion and thermodynamic part of the photo-corrosion of various composites developed by different group across the globe, so that Titania based nanocomposites could be commercially utilized.
European Chemical Bulletin, 2017
Sols prepared by chelation of titanium n-butoxide, Ti(OC4H9)4, with ethyl acetoacetate, C6H10O3, in various ratios were slowly hydrolyzed, and the obtained gels were investigated using Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. The gels were thermally treated at 350 °C, and the products were investigated using X-ray diffraction, N2 gas adsorption-desorption isotherms and diffuse reflectance UV-Vis spectroscopy. Photocatalytic activity assessment was obtained through degradation process of methylene blue under UV light. From the results obtained, the relationships between gel structure and titania crystallite size, specific surface area, bandgap, and photocatalytic activity, as the most relevant parameters, were discussed. The alkoxide modification affected the gel structure, as well as the properties of the final material. However, the sample prepared from unmodified Tin -butoxide yielded the most favorable properties.
Journal of Materials Science: Materials in Electronics, 2019
Biomaterial assisted green synthesis of metal oxide nanoparticles plays a vital role as an eco-friendly alternate to chemical templated approach, in enhancing the physico-chemical properties of the solids. Herein, we have reported the synthesis of mesoporous titania nanoparticles by sol-gel method with the assistance of green tea extract (GTE). The synthesized catalysts were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Thermo gravimetric (TG), Brunauer-Emmett-Teller (BET), diffused reflectance spectroscopy UV-Visible (DRS-UV), scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) analyses. The resulting nano titania exhibited excellent mesoporosity with increased surface area compared to control nano titania as evidenced from BET analysis. XRD results showed that highly crystalline anatase titania nanoparticles could be derived through controlled hydrolysis. Green tea extract also aided in shifting the optical absorption edge of titania towards the visible light region and enabled nano titania to function as an efficient photocatalyst for the photodegradation of Congo red, a model organic pollutant, under solar irradiation. Green tea extract was proved to be a suitable template for the synthesis of visible light active titania with good crystallite characteristics. Hence, it could be proposed as an environmentally benign alternate to the chemical templates for the sol-gel synthesis of titania nanoparticles.