Photocatalytic Reduction of Methyl Orange Using Titania Photocatalyst Codoped with Nitrogen and Gadolinium under Visible Light Illumination

2009 ◽  
Vol 79-82 ◽  
pp. 2127-2130 ◽  
Author(s):  
Song Tao Gu ◽  
Xin Wang ◽  
Qiang Liu ◽  
Hao Quan Liu ◽  
Gui Jun Jiang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Synergistic Effects ◽  
Sol Gel ◽  
Visible Region ◽  
Light Illumination ◽  
Active Nitrogen ◽  
Doped Tio2 ◽  
Codoped Tio2

A visible-light-active nitrogen and gadolinium codoped TiO2 catalyst was synthesized by the sol-gel route. For comparison, Gd-doped sample, N-doped sample, and pure titania were prepared through the same method, without adding the corresponding dopants. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD) and Uv-vis spectra. The results showed that the codoped photocatalyst exhibited a smaller size than the undoped titania. The transformation from anatase to rutile was suppressed by doping with N and Gd atoms. Furthermore, the absorbance spectra of N, Gd-codoped TiO2 exhibited a significant red shift to the visible region. The photocatalytic activity of N, Gd-codoped TiO2 was evaluated by photodegradation of methyl orange under visible light irradiation. This codoped sample exhibited enhanced photocatalytic activity compared to N-doped TiO2, Gd-doped TiO2, and pure TiO2. The improvement of the photocatalytic activity was ascribed to the synergistic effects of the N and Gd co-doping.

Degradation of Indoor Ammonia Using TiO2 Thin Film Doped with Iron(III) under Visible Light Illumination

2013 ◽  
Vol 668 ◽  
pp. 136-139
Author(s):  
Shuai Jie Wang ◽  
Hao Yu ◽  
Xue Qin Gao
Keyword(s):  
Thin Film ◽  
Visible Light ◽  
Tio2 Thin Film ◽  
Sol Gel ◽  
Visible Region ◽  
Reaction Rate Constant ◽  
Light Illumination ◽  
Doping Amount ◽  
Doped Tio2 ◽  
Vis Spectroscopy

A type of titania thin film doped with iron(III) was prepared by means of sol-gel method to degrade indoor ammonia (NH3) under visible light irradiation. The photocatalysts was characterized by X-ray diffraction (XRD) and UV-vis spectroscopy. The results demonstrated that the adsorption edge of doped TiO2 thin film had red shifts and the doped TiO2 thin film had a stronger absorption than undoped TiO2 thin film in the visible region. Doping amount of Fe(III) effected the photocatalytic actitivity of Fe-doped TiO2 thin film significantly. The optimal doping amount of Fe(III) was 1%(mole fraction). Using the optimal Fe-doped TiO2 thin film, the removal percentage of NH3 after 9h phtocatalytic reaction under visible light reached 53.1%. The degradation reaction of NH3 was successfully described by the pseudo first-order kinetics. The reaction rate constant decreased with the increase of initial concentration of NH3, which reflected that there was oxidation competition between NH3 and its intermediate during the photocatalytic process.

scholarly journals Green Synthesis of N/Zr Co-Doped TiO2 for Photocatalytic Degradation of p-Nitrophenol in Wastewater

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Visible Region ◽  
Chemical Properties ◽  
Pure Tio2 ◽  
Molar Ratio ◽  
Xps Spectra ◽  
Doped Tio2 ◽  
Co Doped

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.

Cr Doped TiO2 Supported on TUD-1 Photocatalyst for Dye Photodegradation

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Ooi Yee Khai ◽  
Leny Yuliati ◽  
Siew Ling Lee
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Xrd Analysis ◽  
Bandgap Energy ◽  
Doped Tio2 ◽  
Visible Light Driven ◽  
Synthesized Materials

New visible light driven photocatalysts of 1 mol% Cr doped TiO2 supported on TUD-1 have been successfully synthesized. The Cr-TiO2/xTUD-1 (x = 10, 20, 30, 40 and 50) photocatalysts were prepared via surfactant-free sol-gel method followed by wet impregnation procedures. XRD analysis revealed that both TiO2 and Cr were incorporated in the highly porous siliceous matrix. FTIR analysis showed the existence of Si-O-Ti in all the materials. As observed, tetrahedral-coordinated Ti species were dominant in Cr-TiO2/10TUD-1, Cr-TiO2/20TUD-1 and Cr-TiO2/30TUD-1. Meanwhile, octahedral- coordinated Ti species were the dominant species in Cr-TiO2/40TUD-1 and Cr-TiO2/50TUD-1. It has been demonstrated that the amount of TUD-1 as photocatalyst support affected the wavelength response and the bandgap energy of the resulting materials. All the materials have bandgap energy of ~2.9 eV. The photocatalytic performance of the synthesized materials was tested out in dye photodegradation under visible light irradiation at 298 K for 5 hours. Results showed that all Cr-TiO2/TUD-1 materials had higher photocatalytic activity than that of Cr-TiO2. This could be explained by the high surface area and porosity provided by TUD-1 in enhancing the adsorption and diffusivities of the dye molecules, hence leading to the promising photocatalytic activity. Among the materials prepared, Cr-TiO2/30TUD-1 appeared as the most superior photocatalyst which gave the highest dye photodegradation.

scholarly journals Sol-gel template synthesis of mesoporous carbon-doped TiO2 with photocatalytic activity under visible light

2018 ◽  
Vol 5 (9) ◽  
pp. 17422-17430 ◽  
Author(s):  
Evgeni Ovodok ◽  
Hanna Maltanava ◽  
Sergey Poznyak ◽  
Maria Ivanovskaya ◽  
Alexander Kudlash ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Template Synthesis ◽  
Mesoporous Carbon ◽  
Sol Gel ◽  
Doped Tio2 ◽  
Carbon Doped

Photocatalytic Degradation of Methylene Blue Using Visible Light Active N-Doped ZnO

2015 ◽  
Vol 1101 ◽  
pp. 299-302 ◽  
Author(s):  
Hanggara Sudrajat ◽  
Sandhya Babel
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Nitrogen Doping ◽  
Spectral Response ◽  
Aqueous Suspension ◽  
Visible Region ◽  
Active Nitrogen ◽  
Visible Light Active ◽  
Doped Zno

A visible light active nitrogen-doped ZnO (N-ZnO) was synthesized using a solvent-free mechanochemical method and applied to degrade methylene blue (MB) dye in aqueous suspension. Results showed that nitrogen doping improved the photocatalytic activity of pristine ZnO by extending its spectral response to visible region. Using 2 g/L of N-ZnO, 98% MB with the initial concentration of 10 mg/L could be degraded within 2 h at pH 7 under 11.3 klux of visible light irradiation. After 6th run, it still exhibited appreciable photocatalytic activity with 94% MB degradation, indicating its high reusability though a simple pretreatment was performed.

Synthesis, Characterization and Photocatalytic Activity of Nb-Doped TiO2 Nanoparticles

2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Doped Tio2 ◽  
X Ray ◽  
Vis Spectroscopy

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.

Preparation of TiO2 Nanoparticles Doped with Cs+ and Sr2+ and Their Photocatalytic Activity under Solar Light

2010 ◽  
Vol 113-116 ◽  
pp. 1945-1950 ◽  
Author(s):  
Jie Luo ◽  
Xin Yuan Yang ◽  
De Liang Li
Keyword(s):  
Photocatalytic Activity ◽  
Anatase Phase ◽  
Sol Gel ◽  
Visible Region ◽  
Solar Light ◽  
Tetrabutyl Titanate ◽  
Strontium Nitrate ◽  
Doped Tio2 ◽  
As Doping ◽  
Xrd Patterns

Using cesium nitrate and strontium nitrate as doping metal ions source, Cs-doped TiO2 and Sr-doped TiO2 photocatalysts were successfully synthesized through the hydrolysis of tetrabutyl titanate by an acid-catalyzed sol-gel method. The photocatalytic activities of these catalysts prepared at 600 °C for 2 h were evaluated by the degradation of methyl orange in aqueous solution under solar light irradiation, and the as-prepared samples with higher photocatalytic efficiency were characterized by means of X-ray diffraction (XRD) and UV-Vis absorption spectroscopy. The XRD patterns indicate that the crystal structure still remains as anatase phase for the doped samples, and the average crystal size of TiO2, 0.1 at% Cs-doped TiO2 and 0.3 at% Sr-doped TiO2 is 21.3, 13.1 and 10.8 nm, respectively. The band gap absorption shows red shift to the visible region for the doped samples from the UV-Vis spectrogram. The results show that the photocatalytic activity of TiO2 nanoparticles doped with Cs+ and Sr2+ exhibits a significant improvement and their degradation efficiencies are more than 30% in comparison with those of TiO2 under the same condition, and the optimal doping concentration is determined to be 0.1 at% and 0.3 at% for Cs+ and Sr2+, respectively.

scholarly journals Enhanced Visible Light Photocatalytic Activity of Mesoporous AnataseTiO2Codoped with Nitrogen and Chlorine

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Xiuwen Cheng ◽  
Xiujuan Yu ◽  
Zipeng Xing ◽  
Lisha Yang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Band Gap ◽  
Light Absorption ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Visible Region ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Anatase mesoporous titanium dioxide codoped with nitrogen and chlorine (N-Cl-TiO2) photocatalysts were synthesized through simple one-step sol-gel reactions in the presence of ammonium chloride. The resulting materials were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflection spectrum (UV-vis DRS). XRD results indicated that codoping with nitrogen and chlorine could effectively retard the phase transformation of TiO2from anatase to rutile and the growth of the crystallite sizes. XPS revealed that nitrogen and chlorine elements were incorporated into the lattice of TiO2through substituting the lattice oxygen atoms. DRS exhibited that the light absorption of N-Cl-TiO2in visible region was greatly improved. As a result, the band gap of TiO2was reduced to 2.12 eV. The photocatalytic activity of the as-synthesized TiO2was evaluated for the degradation of RhB and phenol under visible light irradiation. It was found that N-Cl-TiO2catalyst exhibited higher visible light photocatalytic activity than that of P25 TiO2and N-TiO2, which was attributed to the small crystallite size, intense light absorption in visible region, and narrow band gap.

Characterization and activity of visible-light driven TiO2 photocatalyst doped with tungsten

2010 ◽  
Vol 62 (9) ◽  
pp. 2128-2133 ◽  
Author(s):  
T. Putta ◽  
M. C. Lu ◽  
J. Anotai
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Anatase Phase ◽  
Sol Gel ◽  
Light Illumination ◽  
Visible Light Region ◽  
Light Region ◽  
Acid Type ◽  
Visible Light Driven ◽  
Amorphous Tio2

This research aimed to expand the activity of TiO2 down to the visible light region by modifying the sol-gel conditions and doping with tungsten. The optimum conditions for calcination temperature, acid type, and heating rate were 200°C, HNO3, and 1°C/min, respectively. The undoped TiO2 synthesized under these conditions could significantly absorb the visible light whereas the commercial Degussa P-25 could not. The absorptivity decreased sequentially as the wavelength increased from 400 to 700 nm. Within 6 h of 2-W blue-light illumination, 23% of 0.1 mM 2-chlorophenol was removed. The XRD result showed that the crystalline was anatase phase. The visible-light absorption property of the TiO2 became even better when doped with tungsten. At the optimum W to TiO2 ratio of 0.5%, the degradation of 0.1 mM 2-chlorophenol increased to 53% indicating a higher photocatalytic activity. Both crystalline and amorphous TiO2 could exhibit the photocatalytic activity under the visible light region.

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