Synthesis and Characterization of Photocatalytic TiO2-ZnFe2O4 Nanoparticles

2005 ◽  
Vol 876 ◽  
Author(s):  
Sesha S. Srinivasan ◽  
Jeremy Wade ◽  
Elias K. Stefanakos
Keyword(s):  
Visible Light ◽  
Low Cost ◽  
Anatase Phase ◽  
Solar Spectrum ◽  
Rutile Phase ◽  
Oxidation Potential ◽  
Narrow Bandgap ◽  
Visible Wavelengths ◽  
Indoor Lighting

AbstractThe wide bandgap semiconductor TiO2 has become the dominant UV-activated photocatalyst in the field of air and water detoxification because of its high stability, low cost, high oxidation potential and chemically favorable properties. The demand for visible-light activated photocatalytic systems is increasing rapidly; however, currently, the efficiency and availability of photocatalysts that can be activated effectively by the solar spectrum and particularly indoor lighting is severely limited. In this paper, a new coprecipitation/hydrolysis synthesis route is used to create a TiO2-ZnFe2O4 nanocomposite that is directed towards extending the photoresponse of TiO2 from UV to visible wavelengths (>400nm). The effect of TiO2's accelerated anatase-rutile phase transformation due to the presence of the coupled ZnFe2O4 narrow bandgap semiconductor is evaluated. The transformation's dependence on pH, calcination temperature, particle size, and ZnFe2O4 concentration has been analyzed using XRD, SEM, and UV-Visible spectrometry. The requirements for retaining the highly photoactive anatase phase present in a ZnFe2O4 nanocomposite are outlined. The visible-light activated photocatalytic activity of the TiO2-ZnFe2O4 nanocomposites have been compared to an Aldrich TiO2 reference catalyst, using a solar-simulated photoreactor for the degradation of phenol.

scholarly journals Synthesis and Characterization of PhotocatalyticTiO2-ZnFe2O4Nanoparticles

2006 ◽  
Vol 2006 ◽  
pp. 1-4 ◽  
Author(s):  
Sesha S. Srinivasan ◽  
Jeremy Wade ◽  
Elias K. Stefanakos
Keyword(s):  
Particle Size ◽  
Photocatalytic Activity ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Synthesis And Characterization ◽  
Narrow Bandgap ◽  
Uv Visible ◽  
Visible Wavelengths ◽  
Reference Catalyst

A new coprecipitation/hydrolysis synthesis route is used to create aTiO2-ZnFe2O4nanocomposite that is directed towards extending the photoresponse ofTiO2from UV to visible wavelengths (>400 nm). The effect ofTiO2's accelerated anatase-rutile phase transformation due to the presence of the coupledZnFe2O4narrow-bandgap semiconductor is evaluated. The transformation's dependence on pH, calcinations temperature, particle size, andZnFe2O4concentration has been analyzed using XRD, SEM, and UV-visible spectrometry. The requirements for retaining the highly photoactive anatase phase present in aZnFe2O4nanocomposite are outlined. The visible-light-activated photocatalytic activity of theTiO2-ZnFe2O4nanocomposites has been compared to an AldrichTiO2reference catalyst, using a solar-simulated photoreactor for the degradation of phenol.

scholarly journals Photocatalytic and Photoelectrochemical Water Splitting on TiO2via Photosensitization

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Saji Thomas Kochuveedu
Keyword(s):  
Visible Light ◽  
Water Splitting ◽  
Uv Light ◽  
Solar Spectrum ◽  
Wide Bandgap ◽  
Oxidation Potential ◽  
Light Region ◽  
Narrow Bandgap ◽  
Visible Light Active ◽  
Bandgap Semiconductors

The search for an alternative to replace conventional fuel has been going on for years due to the limited storage of fossil fuel and excess CO2emission from the fuel. Using H2as fuel has gained wide attention recently, as well as consequently splitting of water into hydrogen and oxygen. Seminal semiconductors such as TiO2and ZnO have their position of CB and VB in alignment with water reduction and oxidation potential, respectively, but their wide bandgap allows them to absorb only UV light of the solar spectrum. Combining narrow bandgap semiconductors or other visible light active sensitizers with TiO2/ZnO is a facile route to exploit the visible light region of the solar spectrum. In this review, I make an attempt to summarize the various photosensitizers used in combination with TiO2for water splitting with recent reports as examples.

Probing the Phase Transition in Nanocrystalline TiO2 Powders by Positron Lifetime (PAL) Technique

2011 ◽  
Vol 319-320 ◽  
pp. 151-159 ◽  
Author(s):  
E.M. Hassan ◽  
Basma A.A. Balboul ◽  
M.A. Abdel-Rahman
Keyword(s):  
Positron Annihilation ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
Positron Annihilation Lifetime ◽  
Nanocrystallite Size ◽  
Heat Treated ◽  
Degussa P25

Positron annihilation techniques (PAT) have recently been successfully employed for the characterization of phase transitions in metals and compounds. In the present study, positron annihilation lifetime (PAL) measurements have been carried out on a nanocrystalline titania (TiO2) in the form of powders that had been heat-treated at temperatures ranging from 300 to 1273K. The PAL spectra were analyzed into two lifetime components. The shorter lifetime τ1 (185-300 ps) is attributed to positron annihilation in vacancies and the longer lifetime τ1 (400-580 ps) to positrons in microviods at interfaces. The rutile phase of TiO2 powders was utilized as a reference in order to compare their behavior with the commercially supplied and widely available anatase phase (Degussa P25). The influence of the heat-treatment upon the nanostructure during the transition of the anatase to rutile phase were also investigated by X-ray diffraction (XRD), TEM and BET surface area methods. Understanding of this effect is expected to enhance our knowledge of the morphology and nanocrystallite size of TiO2 powders and their T-dependence, and hence their physical properties.

Characterization of Fibers Electrospun from Organometallic Tin Precursors in a Polymer Binder

2006 ◽  
Vol 948 ◽  
Author(s):  
Christopher Rodd ◽  
Jorge J. Santiago-Avilés
Keyword(s):  
Tin Oxide ◽  
Morphological Changes ◽  
Low Cost ◽  
Rutile Phase ◽  
Optical Microscope ◽  
Component Separation ◽  
Raman Spectrometry ◽  
Sensor Applications ◽  
Fiber Deposition

ABSTRACTElectrospinning has been thought of as an effective, low cost technique for producing nanofibers for use in gas sensor applications with nanofibers of tin oxide showing particular promise in this area. Critical to the success of tin oxide in these applications are nanowires with a rutile phase structure and well defined current-voltage characteristics which requires controlled fiber diameters. This paper reports on the characterization of the pre and post sintered fibers deposited via electrospinning of two different tin precursor chemicals, dimethyl dineodecanoate tin and dimethyl dichloro tin, both spun within a polyethylene oxide / chloroform binder system. Both tin precursor systems were evaluated at different concentration levels to investigate morphological changes due to concentration. Mats of fibers were spun on silicon wafers and sintered at 600°C for 2 hours. Morphology was characterized by optical microscope while chemical composition was determined via Raman spectrometry. Fibers of dimethyl dineodecanoate tin were found be ∼30μm in diameter and to have considerable component separation upon deposition. After sintering, SnO2 islands were found but there was no fiber appearance. Fibers of dimethyl dichloro tin were found to be ∼10μm in diameter and lacked the component separation seen in the other tin precursor system with some SnO2 domains found directly inline with initial fiber deposition. Comparison of results from both systems shows that the interaction of the polymer and tin precursor is of paramount importance for development of micro- or nanosized ceramic wires deposited by electrospinning.

scholarly journals Photocatalytic Hydrogen or Oxygen Evolution from Water over S- or N-Doped TiO2under Visible Light

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Kazumoto Nishijima ◽  
Takaaki Kamai ◽  
Naoya Murakami ◽  
Toshiki Tsubota ◽  
Teruhisa Ohno
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Water Oxidation ◽  
Photocatalytic Oxidation ◽  
High Efficiency ◽  
Uv Light ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Activity Level ◽  
Light Irradiation

S- or N-doping ofTiO2powder having an anatase or rutile phase extended the photocatalytic activity for water oxidation and reduction under UV light and visible light irradiation. For the reduction of water, anatase-dopedTiO2showed higher level of activity than that of dopedTiO2having a rutile phase using ethanol as an electron donor. Furthermore, the activity level of S-dopedTiO2for hydrogen evolution was higher than that of N-dopedTiO2photocatalysts under visible light. Photocatalytic oxidation of water on dopedTiO2having a rutile phase proceeded with fairly high efficiency whenFe3+ions were used as electron acceptors compared to that on dopedTiO2having an anatase phase. In addition, water splitting under visible light irradiation was achieved by construction of a Z-scheme photocatalysis system employing the dopedTiO2having anatase and rutile phases forH2andO2evolution and theI−/IO3−redox couple as an electron relay.

scholarly journals Preparation and Characterization of XRD Nano Cu-TiO2 using Sol-Gel Method

2018 ◽  
Author(s):  
Arizka Tamarani ◽  
Rahadian Zainul ◽  
Indang Dewata
Keyword(s):  
Crystallite Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
Rutile Phase ◽  
Doping Agent ◽  
Gel Method ◽  
Sol Gel Method ◽  
Temperature Range

One of the reported doping agent to increase TiO2 activity is Cu. In this research, TiO2 was prepared by So-Gel method. Preparation was performed by calcinaton at the temperature range of 400, 500, 600ᵒC for 2 hours with a corresponding dopan concentration of 0%, 1%, 3%, 5% mol of TiO2. The nanoparticle materials was characterized using XRD. It is found that anatase phase occur in the calcinations temperature of 400ᵒC and transform to rutile phase at 500ᵒC. The crystallite size of Cudoped TiO2 with dopan concentration of 5% are found 4.63 nm, 8.70 nm, 6.09 nm respectively at 400ᵒC, 500ᵒC, 600ᵒC.

Sol-Gel Synthesis and Characterization of TiO2-Based Photocatalyst and its Photoactivity Research

2013 ◽  
Vol 864-867 ◽  
pp. 613-616
Author(s):  
Xue Mei Qi ◽  
Xin Yuan Zhu ◽  
Jiang Wu ◽  
Yu Wu ◽  
Han Cheng Luo
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Great Influence ◽  
Rutile Phase ◽  
Xrd Diffraction ◽  
Sol Gel Process ◽  
Photocatalytic Activities ◽  
Stirring Time ◽  
Sol Gel Synthesis

The TiO2-based photocatalysts have been synthesized by using sol-gel process and their photocatalytic activities were studied by the degradation of methylene blue (MB). It was shown that the calcination temperature has great influence on the crystalline phase transition of TiO2. For all the samples (Ag-doped and undoped TiO2photocatalysts) calcined at 573K, only anatase phase was observed from XRD diffraction spectra and the intensity of peaks is weak. After the calcined at 773K, a mixture of anatase-rutile phase appeared. The contents of rutile phase were about 85% and77% for undoped and Ag-adopted TiO2photocatalysts.There were only rutile phases for all the TiO2photocatalysts calcined at 973K observed from XRD diffraction spectra. Magnetically stirring time of A solution before added B had no obvious effects on the polymorphs transition of TiO2.

The Preparation and Visible Light Photocatalytic Activity of ZnO-TiO2 Nanofibers

2012 ◽  
Vol 472-475 ◽  
pp. 3441-3444 ◽  
Author(s):  
Qian Xiong ◽  
Mi Zhou ◽  
Xin Qian
Keyword(s):  
Visible Light ◽  
Composite Nanofibers ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Chemical Components ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Two Temperatures ◽  
Visible Light Photocatalytic ◽  
Calcination Treatment

ZnO-TiO2 composite nanofibers were prepared by using the electrospun fibers of PVP/ZnSO4/ Ti(OiPr)4 composite as precursor, and through calcination treatment. The chemical components, structures and morphology were characterized by FT-IR, XRD, SEM, respectively. The photocatalytic activities of the catalysts were investigated by photocatalystic degradation of Rhodamine B under visible-light irradiation. It was found that the ZnO-TiO2 composite nanofibers photocatalyst calcined at 600 °C which was mixed the anatase phase and rutile phase, showed higher photocatalytic activities than those calcined at other two temperatures. This result was expected as a new morphology of photocatalysts to degrade the organic pollutants in the sun.

Preliminary design and characterization of a low-cost and low-power visible light positioning system

2019 ◽  
Vol 58 (26) ◽  
pp. 7181
Author(s):  
Jordan Lui ◽  
Anna Maria Vegni ◽  
Lorenzo Colace ◽  
Alessandro Neri ◽  
Carlo Menon
Keyword(s):  
Low Power ◽  
Visible Light ◽  
Low Cost ◽  
Positioning System ◽  
Preliminary Design
Sign in / Sign up

Export Citation Format

Share Document