THE EFFECT OF CRYSTAL FORM OF N-DOPED TITANIUM DIOXIDE ON VISIBLE-LIGHT PHOTOCATALYTIC ACTIVITY

2009 ◽  
Vol 16 (04) ◽  
pp. 563-567 ◽  
Author(s):  
JIWEI ZHANG ◽  
JINGWEI ZHANG ◽  
ZHENSHENG JIN ◽  
ZHISHEN WU ◽  
ZHIJUN ZHANG
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Elevated Temperatures ◽  
Removal Rate ◽  
Crystal Form ◽  
Crystal Forms ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Light Activity ◽  
Visible Light Photocatalytic

TiO 2 samples with different crystal forms were treated in flowing NH 3 at elevated temperatures to fabricate N -doped TiO 2 photocatalysts with different crystal forms. The resulting N -doped TiO 2 photocatalysts were characterized by means of X-ray diffraction, transmission electron microscopy, diffusion reflectance spectrometry, and X-ray photoelectron spectroscopy. The visible-light photocatalytic activity of the catalysts was evaluated by measuring the photocatalyzed removal rate of propylene. Results indicate that the visible-light activity of N -doped TiO 2 photocatalysts is highly dependent on the crystal form. Namely, N -doped anatase TiO 2 has the highest visible-light activity, while the visible-light activity of N -doped TiO 2 photocatalysts decreases with decreasing content of anatase phase and increasing content of rutile phase. In addition N -doped rutile TiO 2 has no visible-light photocatalytic activity.

scholarly journals Visible-Light Photocatalytic Activity of N-Doped TiO2Nanotube Arrays on Acephate Degradation

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Xinlei Zhang ◽  
Juan Zhou ◽  
Yufen Gu ◽  
Ding Fan
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Nanotube Arrays ◽  
Optical Absorption Edge ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Uv Visible ◽  
Anodic Oxidation Method ◽  
Visible Light Photocatalytic ◽  
Nitrogen Doped Titanium Dioxide

Highly ordered nitrogen-doped titanium dioxide (N-doped TiO2) nanotube arrays were prepared by anodic oxidation method and then annealed in a N2atmosphere to obtain N-doped TiO2nanotube arrays. The samples were characterized with scanning electron microscope (SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectrum (XPS), and UV-visible spectrophotometry (UV-vis) spectrum. Degradation of the insecticide acephate under the visible light was used as a model to examine the visible-light photocatalytic activity of N-doped TiO2nanotube arrays. The results show that N type doping has no notable effects on the morphology and structure of TiO2nanotube arrays. After N type doping, the N replaces a small amount of O in TiO2, forming an N–Ti–O structure. This shifts the optical absorption edge and enhances absorption of the visible light. N-doped TiO2nanotube arrays subjected to annealing at 500°C in N2atmosphere show the strongest photocatalytic activity and reach a degradation rate of 84% within 2 h.

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.

High-Efficiency Preparation of N-Doped Titania with High Visible Light Photocatalytic Activity Using Composite N Precursor

2015 ◽  
Vol 645-646 ◽  
pp. 368-374
Author(s):  
Yu Long Hu ◽  
Xiao Dong Zhang ◽  
Hong Fang Liu ◽  
Xing Peng Guo
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
High Efficiency ◽  
Thermo Gravimetric Analysis ◽  
Ammonium Hydroxide ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Photocatalytic Activities ◽  
Visible Light Photocatalytic

N-doped TiO2 nanoparticle powders were prepared efficiently by the sol-gel method using triethylamine and ammonium hydroxide as composite N precursor. The as-prepared N-doped TiO2 precursor powders were calcined at 300°C in air for 3 h and subsequently annealed at 300°C in air for 2.5 h. The samples were characterized by X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, and X-ray photoelectron spectroscopy. The visible light photocatalytic activities of as-prepared samples were evaluated by photodecomposition of methyl orange (MO). The results show that the as-prepared samples have high visible light photocatalytic activities. Triethylamine produces the N-species doped in TiO2 lattice responsible for the high visible light photocatalytic activity. Ammonium hydroxide makes the gel of the TiO2 nanoparticles nitrided by triethylamine gelate further and facilitates significantly the centrifugation of the gel. An annealing treatment can eliminate effectively the outer N species caused by ammonium hydroxide and the surface organic residues, improve effectively crystallinity, and retain the N species caused by triethylamine.

Effect of Calcination Temperature on Light Absorption and Visible Light Photocatalytic Activity of N Doped TiO2 Nano-Crystalline

2020 ◽  
Vol 12 (3) ◽  
pp. 449-453 ◽  
Author(s):  
Bo Wang ◽  
Ruiling Zhang ◽  
Jin Xu ◽  
Songyan Qin ◽  
Jiajun Zheng ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Hydroxyl Groups ◽  
Visible Light Region ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Nano Crystalline ◽  
Light Region ◽  
Visible Light Photocatalytic

N doped TiO2 nano-crystalline was prepared through hydrolysis-precipitation process in the presence of ammonia water. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). It was found that N was incorporated into the lattice of TiO2 through substituting lattice oxygen atoms and coexisted in the forms of substitutional N (O–Ti–N) and interstitial N (Ti–O–N). Further, doping with N could greatly improve the phase transformation of TiO2 from rutile to anatase and light absorption in visible light region. The high visible light photocatalytic activity for the degradation of RhB of N doped TiO2 was mainly attributed to the small crystallite size, mixed phase composition, intense light absorption in visible light region, narrow band gap energy and surface hydroxyl groups.

scholarly journals Synthesis, Characterization, and Investigation of Visible Light Photocatalytic Activity of C Doped TiO2/CdS Core-Shell Nanocomposite

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Atul B. Lavand ◽  
Yuvraj S. Malghe ◽  
Suraj H. Singh
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Region ◽  
Cds Nanoparticles ◽  
Core Shell ◽  
Visible Absorption ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Uv Visible ◽  
Visible Light Photocatalytic

Carbon (C) doped TiO2/CdS core-shell nanocomposite (C/TiO2/CdS) was synthesized using microemulsion method. Synthesized powder was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and UV-visible spectrophotometery. TEM images reveal that C/TiO2/CdS core-shell heterostructure is successfully prepared with CdS as a core and C doped TiO2 as a shell. UV-visible absorption spectra show that CdS nanoparticles act as a sensitizer and effectively enhance the photoabsorption capacity of C/TiO2/CdS nanocomposite in visible region. Visible light photocatalytic activity of synthesized nanocomposite was evaluated for the degradation of methylene blue. C/TiO2/CdS core-shell nanocomposite exhibits better photocatalytic activity as compared to bare TiO2, CdS, CdS/TiO2, and C doped TiO2.

Influence of Pt and Pd Modification on the Visible Light Photocatalytic Activity of N-Doped Titania Photocatalysts

2016 ◽  
Vol 16 (4) ◽  
pp. 3570-3576 ◽  
Author(s):  
Yulong Hu ◽  
Fu Dong ◽  
Hongfang Liu ◽  
Xingpeng Guo
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Metallic State ◽  
Visible Light Region ◽  
Electron Hole ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Light Region ◽  
Doped Titania ◽  
Visible Light Photocatalytic

Pd and Pt modified N-doped titania nanoparticle powders were prepared by a facile sol–gel method. Nitrogen doping and metal modification were carried out simultaneously during the preparation process. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and X-ray photoelectron spectroscopy (XPS). The visible light photocatalytic activities of the asprepared samples were evaluated by analyzing their effect on the photocatalytic decomposition of methyl orange (MO). The chemical state of the metal is the key factor determining the performance of metal modified N-doped titania. The Pd used to modify the N-doped titania (Pd-NT) in our study was of the PdOx(x≤2) species, which increased the absorbance in the visible light region, decreased the recombination of photo-generated electron–hole pairs, and resulted in a significant enhancement in the visible light photocatalytic activity. The Pt species used to modify the N-doped titania (Pt-NT) was mainly in the metallic state, which resulted in a decrease in the absorbance in the visible light region, and an increase in the recombination of photo-generated electron–hole pairs. Pt modification led to a deterioration in the visible light photocatalytic activity of the material.

scholarly journals Visible light photocatalytic activity of TiO2 deposited on activated carbon

2013 ◽  
Vol 11 (3) ◽  
pp. 464-470 ◽  
Author(s):  
Alexander Eliyas ◽  
Ljutzkan Ljutzkanov ◽  
Irina Stambolova ◽  
Vladimir Blaskov ◽  
Sasho Vassilev ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Activated Carbon ◽  
Visible Light ◽  
Uv Light ◽  
Original Method ◽  
Light Illumination ◽  
Porous Texture ◽  
Visible Light Photocatalytic Activity ◽  
Light Activity ◽  
Visible Light Photocatalytic

AbstractAbstract Four photocatalyst samples, prepared from beech sawdust, were synthesized by an original method, combining pyrolysis and impregnation — two of them: TiO2 + activated carbon and other two — only activated carbon. The pyrolysis process has been carried out at two different temperatures — 680°C and 830°C. The prepared samples were characterized by a series of methods — XRD, BET, SEM and DTA/TG. The most important result was achieving visible light photocatalytic activity with an azo dye pollutant for both materials. The TiO2/AC-680°C sample demonstrated higher activity under visible light illumination than the TiO2/AC-830°C sample. The visible light activity was attributed to the active carbon component in the composite materials, which was evidenced by the photocatalytic tests with bare carbon (without any TiO2) manifesting visible light activity. The AC-680°C carbon was superior to the AC-830°C under visible illumination probably due to its higher specific surface area and porous texture. UV-light testing of the photocatalytic activity revealed that the TiO2/AC-680°C sample was higher than that of the TiO2/AC-830°C under polychromatic UV-A illumination (320–400 nm with a maximum at l = 365 nm). The TiO2/AC-680°C sample was also more efficient with the monochromatic UV-C illumination (l = 254 nm). Graphical abstract

Characterization and Visible-Light Photocatalytic Activity of Nano-Bi2MoO6 Catalysts Prepared by Hydrothermal Process

2011 ◽  
Vol 117-119 ◽  
pp. 803-806
Author(s):  
Pei Song Tang ◽  
Hai Feng Chen ◽  
Feng Cao ◽  
Guo Xiang Pan ◽  
Min Hong Xu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Degussa P25 ◽  
Uv Visible ◽  
Visible Light Photocatalytic

The Nano-Bi2MoO6was prepared using Bi(NO3)3•5H2O and Na2MoO4•2H2O as starting materials by a hydrothermal process. The prepared Bi2MoO6product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the prepared nano-Bi2MoO6show narrow band gap of 2.88 eV. Consequently, the prepared nano-Bi2MoO6show high visible-light photocatalytic activity for decomposition of Rhodamine B in comparison with the commercial Degussa P25, which was ascribed to the visible-light absorption.

Synthesis of BiVO4/Bi2VO5.5 Heterogeneous Nanostructures with Enhanced Visible Light Photocatalytic Activity

2016 ◽  
Vol 847 ◽  
pp. 211-217
Author(s):  
Jian Min Wang ◽  
Feng Cao ◽  
Xin Lv ◽  
Song Li ◽  
Jia Jia Cai ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Separation Efficiency ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Driven ◽  
Visible Light Photocatalytic

BiVO4/Bi2VO5.5 heterogeneous nanostructures with enhanced visible light photocatalytic activity were successfully prepared by a facile one-pot solvothermal method, where diethylene glycol (DEG) was used as the solvent. The as-prepared products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectrometry (XPS) and UV-Vis absorption spectroscopy. The results revealed that the molar ratio of Bi3+ to VO43- played an important role in the formation of crystal and morphology. These BiVO4/Bi2VO5.5 heterogeneous nanostructures exhibited higher visible-light-driven photocatalytic efficiency compared to the pure BiVO4 and Bi2VO5.5. For the methyl orange (MO) degradation efficiency of BiVO4/Bi2VO5.5 heterogeneous nanostructures under visible light irradiation, about 95% of MO was degraded within 40min, which is much higher than pure BiVO4 and Bi2VO5.5. The enhancement of photocatalytic activity can attribute to the promoted light absorption capability and the separation efficiency of photo-generated electron-hole pairs.

scholarly journals Cu-doped TiO2 brookite photocatalyst with enhanced visible light photocatalytic activity

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yunling Zou ◽  
Xianshou Huang ◽  
Tao Yu ◽  
Xiaoqiang Tong ◽  
Yan Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Abstract Cu-doped TiO2 having a brookite phase and showing enhanced visible light photocatalytic activity was synthesized using a mild solvothermal method. The as-prepared samples were characterized by various techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy. Photocatalytic activity of Cu-doped brookite TiO2 nanoparticles was evaluated by photodegradation of methylene blue under visible light irradiation. The X-ray diffraction analysis showed that the crystallite size of Cu-doped brookite TiO2 samples decreased with the increase of Cu concentration in the samples. The UV-Vis diffuse reflectance spectroscopy analysis of the Cu-doped TiO2 samples showed a shift to lower energy levels in the band gap compared with that of bare phase brookite TiO2. Cu doped brookite TiO2 can obviously improve its visible light photocatalytic activity because of Cu ions acting as electron acceptors and inhibiting electron-hole recombination. The brookite TiO2 sample with 7.0 wt.% Cu showed the highest photocatalytic activity and the corresponding degradation rate of MB (10 mg/L) reached to 87 % after visible light illumination for 120 min, much higher than that of bare brookite TiO2 prepared under the same conditions (78 %).

Sign in / Sign up

Export Citation Format

Share Document