Titania-based nanocomposites for solar photocatalysis (original) (raw)
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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.
Next generation of pure titania nanoparticles for enhanced solar-light photocatalytic activity
Journal of Materials Science: Materials in Electronics, 2017
TiO 2 nanoparticles are renowned for its photocatalytic degradation. Herein, Oxygen-rich TiO 2 nanosphere and TiO 2 nanorods have been prepared by photon induced method (PIM). This facial preparation method is cost effective and produce pure anatase phased TiO 2 nanoparticles with high stability. The morphology of the prepared TiO 2 samples for various preparation times have been analyzed using HRTEM and HRSEM. As the preparation time is increased, a morphological transformation from nanorods to nanospheres is witnessed. The possible reason behind this transformation has also been discussed. The nature of the samples have been investigated using XRD, FTIR, PL, XPS and UV-Vis spectroscopy. The PIM prepared sample for 8 days show pure anatase phase stability even at a higher calcination temperature of 800 °C. This is correlated with the oxygen richness of the sample. A clear discussion regarding this enhanced phase stability is also presented here. Also, the photocatalytic activity of both the samples have been investigated through the degradation of methylene blue dye. The degradation of methylene blue under sunlight by pure TiO 2 nanosphere is quicker when compared with TiO 2 nanorods and Degussa P25. The reason for the enhanced photodegradation activity of pure TiO 2 nanospheres has also been discussed in detail.
Brief Review on Some Major Factors Affecting Visible Light Activity of Titania Photocatalyst
As sunlight is an excellent source of clean energy, research for harnessing the energy via an efficient photocatalyst that is active under visible light is actively underway. Titania is well accepted as a photosemiconductor and photocatalyst under ultraviolet light. Effort to make it visible light active has been growing. This review article presents some factors involving the photocatalytic activity of titania which is active under visible light in terms of crystallography. Based on recent progress, several suggestions are made for a better visible light active titania. Keywords: Titania; Photocatalyst; Visible Light; Crystal Lattice; Hetero Junction; Excitons; Charge Separation.
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...
2015
The present thesis focused on the development of modified titania nano photocatalysts to synergise enhanced visible light photocatalysis that niched for the destruction of lethal aquatic pollutants. In preliminary phase template TiO2 was successfully synthesised through a facile non-hydrolitic sol-gel technique. The materials chemistry revealed the pristine anatase phase and crystallinity of TiO2. It also demonstrated the influence of crystallinity over photocatalysis efficiency. This was well reflected in photocatalysis evaluation studies under solar irradiation where good crystallinity shown a better photodegradation performance over the non-crystalline. The inherent photocatalytic characteristics of the synthesised TiO2 was modified and enhanced by incorporating the noble characteristic derived from palladium (Pd) and silver (Ag). This was achieved through a smart, ease and sustainable method. The adopted novel method explicitly revealed the capability of sunlight for anchoring t...
Artificial Photosynthesis with Titania Photocatalysts
Natural and Applied Sciences Journal, 2019
Increasing energy demand and global warming due to extensive use of fossil fuels will soon force mankind to use clean and sustainable fuels and artificial photosynthesis is being considered as a promising solution to both problems. Photocatalysis is a light induced process involved in artificial photosynthesis and it will make a great contribution to the solution of environmental problems and generation of renewable energy sources. Titania based photocatalytic materials are one of the widely used materials in artificial photosynthesis research due to their unique chemical and optical properties. Recent research has shown that the activity of titania phases can be improved in the visible light region by several modification techniques. This article aims to present a brief review based on the last 2 decades of global research on the preparation and modification of titania based photocatalysts, their application and importance in artificial photosynthesis and its effect on reducing global warming by the development of a sustainable energy source. This review is mostly based on the PhD thesis of the corresponding author (Yurtsever, 2015).
Visible light induced photocatalytic activity of rare earth titania nanocomposites
Journal of Molecular Catalysis A-chemical, 2008
Water pollution by organic pollutants has been a growing global problem in recent years, for which there is a great demand of efficient technologies for wastewater treatment. Remediation of water by photocatalytic oxidation has several advantages over adsorption or any other conventional techniques. This study reports a easy synthesis technique of a sulfur doped hollow TiO 2 nanocatalyst for photo degradation of organic dye under solar light. The hollow doped TiO 2 nano catalyst has significantly high specific surface area (318.11 m 2 g −1 ) and low band gap (2.5 eV) compared to that of solid particles (130.94 m 2 g −1 and 3.2 eV respectively), as a result it acts as an efficient photocatalyst under solar light. The methylene blue dye degradation ability of this catalyst is shown to be 98.6% compared to that of standard Degussa P25 (30%) as reported before. Additionally, the catalyst is also able to degrade 71% methylene blue dye during fifth times recycling without any further treatment because of its high surface area. So our sulfur doped hollow TiO 2 nanoparticles can be used as a potential photocatalyst for environmental remediation applications. † Electronic supplementary information (ESI) available: Fluorescence spectroscopy, -S7
Chemical Physics Letters, 2005
The carbon-doped titania with high surface area was prepared by temperature-programmed carbonization of K-contained anatase titania under a flow of cyclohexane. This carbon-doped titania has much better photocatalytic activity for gas-phase photo-oxidation of benzene under irradiation of artificial solar light than pure titania. The visible light photocatalytic activity is ascribed to the presence of oxygen vacancy states because of the formation of Ti 3+ species between the valence and the conduction bands in the TiO 2 band structure. The co-existence of K and carbonaceous species together stabilize Ti 3+ species and the oxygen vacancy state in the as-synthesized carbon-doped titania.
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.
International Journal of Photoenergy, 2012
As a consequence of the rapid growth of industry, major problems are created related to energy and environment. Sunlight being one of the most potential alternative source of energy, the development of efficient solar-energy storage systems is an important subject in the fields of science and technology. Here we have reviewed and summarized some of the recent reports on visible responsive photocatalysts. In this review, the influence of various metal oxide photocatalysts on energy production and pollutant removal are presented with special emphasis on titania based photocatalysts. The photoactivity of titania for various pollutant degradation, modified titania (TiO2) systems, their physical and chemical characteristics, and so forth, are described in detail at this juncture. Different methods used to enhance the visible light absorption of TiO2, like doping with metals and nonmetals, coupling with other metal oxides, and so forth, have been discussed. Various applications of photoca...