scholarly journals Growth of g-C3N4Layer on Commercial TiO2for Enhanced Visible Light Photocatalytic Activity

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Min Fu ◽  
Jiazhen Liao ◽  
Fan Dong ◽  
Hongmei Li ◽  
Hongyan Liu
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Weight Ratio ◽  
Photocatalytic Property ◽  
Photogenerated Electron ◽  
Cost Effective ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Novel visible light photocatalytic graphitic carbon nitride/TiO2(g-C3N4/TiO2) composite samples were synthesized by heating mixtures of melamine and commercial TiO2(TO) at different weight ratios. The samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), and UV-visible diffused reflectance spectroscopy (UV-vis DRS). Characterization confirms formation of nanocomposites of g-C3N4/TiO2. At the optimized precursor weight ratio (melamine:mTiO2=2.5), the samples exhibited highest adsorption capacity and visible light photocatalytic activity, measured by degradation of methylene blue (MB). Under visible light irradiation, the excited electrons on the surface of g-C3N4transfer easily to the conduction band (CB) of TiO2via the well-built heterojunction. The g-C3N4/TiO2nanocomposites exhibit enhanced visible light catalytic activity due to increased visible light adsorption and effective separation of photogenerated electron-hole pairs. These g-C3N4/TiO2nanocomposites could find broad applicability in environmental protection due to their excellent visible light photocatalytic property and facile, cost-effective preparation process.

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.

scholarly journals Synthesis and Characterization of Fe-N-S-tri-DopedTiO2Photocatalyst and Its Enhanced Visible Light Photocatalytic Activity

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Biying Li ◽  
Xiuwen Cheng ◽  
Xiujuan Yu ◽  
Lei Yan ◽  
Zipeng Xing
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Crystallite Size ◽  
Photoelectron Spectroscopy ◽  
Visible Region ◽  
Bandgap Energy ◽  
X Ray ◽  
Visible Light Photocatalytic Activity ◽  
Light Absorbance ◽  
Visible Light Photocatalytic

Fe-N-S-tri-dopedTiO2photocatalysts were synthesized by one step in the presence of ammonium ferrous sulfate. The resulting materials were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflection spectrum (UV-Vis DRS). XPS analysis indicated that Fe (III) and S6+were incorporated into the lattice ofTiO2through substituting titanium atoms, and N might coexist in the forms of substitutional N (O-Ti-N) and interstitial N (Ti-O-N) in tridopedTiO2. XRD results showed that tri-doping with Fe, N, and S elements could effectively retard the phase transformation ofTiO2from anatase to rutile and growth of crystallite size. DRS results revealed that the light absorbance edge ofTiO2in visible region was greatly improved by tri-doping with Fe, N, and S elements. Further, the photocatalytic activity of the as-synthesized samples was evaluated by the degradation of phenol under visible light irradiation. It was found that Fe-N-S-tri-dopedTiO2catalyst exhibited higher visible light photocatalytic activity than that of pureTiO2and P25TiO2, which was mainly attributed to the small crystallite size, intense light absorbance in visible region, and narrow bandgap energy.

scholarly journals One-Step Cohydrothermal Synthesis of Nitrogen-Doped Titanium Oxide Nanotubes with Enhanced Visible Light Photocatalytic Activity

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Cheng-Ching Hu ◽  
Tzu-Chien Hsu ◽  
Li-Heng Kao
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Nitrogen Adsorption ◽  
Raw Material ◽  
Factors Affecting ◽  
X Ray ◽  
Nitrogen Doped ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

Nitrogen-doped TiO2nanotubes with enhanced visible light photocatalytic activity have been synthesized using commercial titania P25 as raw material by a facile P25/urea cohydrothermal method. Morphological and microstructural characteristics were conducted by transmission electron microscopy, powder X-ray diffraction, and nitrogen adsorption/desorption isotherms; chemical identifications were performed using X-ray photoelectron spectroscopy, and the interstitial nitrogen linkage to the TiO2nanotubes is identified. The photocatalytic activity of nitrogen-doped TiO2nanotubes, evaluated by the decomposition of rhodamine B dye solution under visible light using UV-vis absorption spectroscopy, is found to exhibit ~ four times higher than that of P25 and undoped titanate nanotubes. Factors affecting the photocatalytic activity are analyzed; it is found that the nitrogen content and surface area, rather than the crystallinity, are more crucial in affecting the photocatalytic efficiency of the nitrogen-doped TiO2nanotubes.

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 Preparation of g-C3N4/MoS2 Composite Material and Its Visible Light Catalytic Performance

2021 ◽  
Author(s):  
Yu Fan ◽  
Yan-ning Yang ◽  
Chen Ding
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Photogenerated Electron ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Calcination Method

Abstract The g-C3N4 nanosheet was prepared by calcination method, the MoS2 nanosheet was prepared by hydrothermal method. The g-C3N4/MoS2 composites were prepared by ultrasonic composite in anhydrous ethanol. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-Vis), and photoluminescence (PL) techniques were used to characterize the materials. The photocatalytic degradation of Rhodamine B (Rh B) by g-C3N4/MoS2 composites with different mass ratios was investigated under visible light. The results show that a small amount of MoS2 combined with g-C3N4 can significantly improve photocatalytic activity. The g-C3N4/MoS2 composite with a mass ratio of 1:8 has the highest photocatalytic activity, and the degradation rate of Rh B increases from 50% to 99.6%. The main reason is that MoS2 and g-C3N4 have a matching band structure. The separation rate of photogenerated electron-hole pairs is enhanced. So the g-C3N4/MoS2 composite can improve the photocatalytic activity. The photocatalytic mechanism was proposed through the active matter capture experiment.

Influence of Ytterbium Doping on the Visible Light Photocatalytic Activity of Mixed Phase TiO2 Nanoparticles

2019 ◽  
Vol 807 ◽  
pp. 18-25
Author(s):  
Fu Chang Peng ◽  
Qi Lai ◽  
Can Yu Zhong ◽  
Yan Cui ◽  
Xian Jie Liao ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Phase Transfer ◽  
Photogenerated Electron ◽  
Mixed Phase ◽  
Fluorescent Light ◽  
Experimental Conditions ◽  
Visible Light Photocatalytic Activity ◽  
Ytterbium Doping ◽  
Visible Light Photocatalytic

The TiO2 nanoparticles with different Yb doping amount were prepared by a facile sol-gel method. The samples were characterized by XRD, TEM, XPS, UV-Vis, and PL, etc. The influence of Yb-doping on structure and visible light photocatalytic activity of mixed phase TiO2 was evaluated by photocatalytic degradation of methylene blue (MB) under the irradiation of fluorescent lamp. The results show that ytterbium appeared two kinds of Yb3+ and Yb2+ valence state on the surface of TiO2. Ytterbium doping can restrain the phase transfer from anatase to rutile, prevent the grain growth, and increase the surface hydroxyl content. Appropriate amount of Yb doping and the proportions of rutile and anatase mixed phase can effectively inhibit the recombination of photogenerated electron and hole, expand the wavelength range of absorption spectrum, and improve the photocatalytic performance of TiO2. Meanwhile, the photocatalytic activity of the Yb-TiO2 samples was the best under the irradiation of fluorescent light when the sintered temperature T=500°C and n(Yb):n(Ti)=0.009, it was 95.2% within 6 h and significantly higher than 56.4% of pure TiO2 under the same experimental conditions.

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.

scholarly journals A Cost-Effective Solid-State Approach to Synthesize g-C3N4Coated TiO2Nanocomposites with Enhanced Visible Light Photocatalytic Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Min Fu ◽  
Junmin Pi ◽  
Fan Dong ◽  
Qiuyan Duan ◽  
Huan Guo
Keyword(s):  
Photocatalytic Activity ◽  
Solid State ◽  
Visible Light ◽  
Environmental Remediation ◽  
Cost Effective ◽  
Solid State Method ◽  
Visible Light Photocatalytic Activity ◽  
Enhanced Absorption ◽  
Light Region ◽  
Visible Light Photocatalytic

Novel graphitic carbon nitride (g-C3N4) coated TiO2nanocomposites were prepared by a facile and cost-effective solid-state method by thermal treatment of the mixture of urea and commercial TiO2. Because the C3N4was dispersed and coated on the TiO2nanoparticles, the as-prepared g-C3N4/TiO2nanocomposites showed enhanced absorption and photocatalytic properties in visible light region. The as-prepared g-C3N4coated TiO2nanocomposites under 450°C exhibited efficient visible light photocatalytic activity for degradation of aqueous MB due to the increased visible light absorption and enhanced MB adsorption. The g-C3N4coated TiO2nanocomposites would have wide applications in both environmental remediation and solar energy conversion.

In Situ Synthesis of Ti3+ Self-Doped TiO2/N-Doped Carbon Nanocomposites and its Visible Light Photocatalytic Performance

NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650088 ◽  
Author(s):  
Chaoyi Wu ◽  
Zhenggang Gao ◽  
Shanmin Gao ◽  
Qingyao Wang ◽  
Zeyan Wang ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Performance ◽  
Electrochemical Impedance ◽  
Photocatalytic Property ◽  
Accelerate Electron ◽  
Photogenerated Electron ◽  
Light Illumination ◽  
Carbon Nanostructure ◽  
X Ray ◽  
Visible Light Photocatalytic

Ti[Formula: see text] self-doped TiO2 (TiO[Formula: see text])/N-doped carbon nanostructure composites were prepared via a facile one-step hydrothermal method to optimize the use of visible light and reduce recombination of photogenerated electrons and holes. The composites were characterized by X-ray diffraction, transmission electron microscopy (TEM), high-resolution TEM, X-ray photoelectron spectroscopy, and Fourier-transform infrared spectroscopy. The amounts of carbon and nitrogen sources affect the morphology and photocatalytic performance. At low amounts of the sources, the N-doped carbon nanostructure is an amorphous film and is well-combined with TiO[Formula: see text] nanoparticles through surface carbon–oxygen groups. At high amounts of the sources, N-doped carbon quantum dots (NCQDs) were obtained, and carbon atoms could substitute for oxygen atoms in the TiO2 lattice to form Ti–C structures, which are responsible for the high photocatalytic activity under visible light illumination. Transient photocurrent response and electrochemical impedance spectroscopy results indicate that the amorphous hybrid film becomes a trap for electrons and that NCQDs can accelerate electron transfer. The improved visible light photocatalytic property for the TiO[Formula: see text]/NCQDs composite can be attributed to the enhancement of light absorption and inhibition of the photogenerated electron–hole recombination of anchored NCQDs.

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.

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