scholarly journals Mesoporous Metal-Containing Carbon Nitrides for Improved Photocatalytic Activities

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jie Luo ◽  
Zhao-Jie Cui ◽  
Guo-Long Zang
Keyword(s):  
Photocatalytic Activity ◽  
Mesoporous Structure ◽  
Hard Template ◽  
Visible Absorption ◽  
Contaminant Degradation ◽  
Photocatalytic Activities ◽  
Carbon Nitrides ◽  
Uv Visible ◽  
Mesoporous Metal ◽  
Positive Effect

Graphitic carbon nitrides (g-C3N4) have attracted increasing interest due to their unusual properties and promising applications in water splitting, heterogeneous catalysis, and organic contaminant degradation. In this study, a new method was developed for the synthesis of mesoporous Fe contained g-C3N4(m-Fe-C3N4) photocatalyst by using SiO2nanoparticles as hard template and dicyandiamide as precursor. The physicochemical properties of m-Fe-C3N4were thoroughly investigated. The XRD and XPS results indicated that Fe was strongly coordinated with the g-C3N4matrix and that the doping and mesoporous structure partially deteriorated its crystalline structure. The UV-visible absorption spectra revealed that m-Fe-C3N4with a unique electronic structure displays an increased band gap in combination with a slightly reduced absorbance, implying that mesoporous structure modified the electronic properties of g-Fe-C3N4. The photocatalytic activity of m-Fe-C3N4for photodegradation of Rhodamine B (RhB) was much higher than that of g-Fe-C3N4, clearly demonstrating porous structure positive effect.

Self-Generated Macrochannel-Structure TiO2/g-C3N4 with High Photocatalytic Activity

2016 ◽  
Vol 69 (4) ◽  
pp. 478 ◽  
Author(s):  
Gaopeng Dai ◽  
Tao Wang ◽  
Suqin Liu ◽  
Ying Liang ◽  
Wen Xu
Keyword(s):  
Photocatalytic Activity ◽  
High Photocatalytic Activity ◽  
Tetrabutyl Titanate ◽  
Mixed Solution ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Sunlight Irradiation ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Oxidative Species

TiO2/g-C3N4 composites with macrochannel structure were successfully synthesised without using templates by the simple dropwise addition of tetrabutyl titanate containing graphitic carbon nitride (g-C3N4) to a water-ethanol mixed solution, which was then calcined at 400°C. The as-prepared samples were characterised by X-ray diffraction, scanning electron microscopy, and UV-visible absorption spectroscopy. The photocatalytic activities of the samples were evaluated by the photocatalytic degradation of methyl orange in an aqueous medium under visible-light and simulated sunlight irradiation. The results show that the g-C3N4 content in TiO2/g-C3N4 composites plays an important role in the formation of macrochannels. Only samples containing less than 10 wt-% of g-C3N4 exhibit macrochannel structure. TiO2/g-C3N4 composites with macrochannel structure displayed enhanced photocatalytic activity. G-C3N4 content exhibited an obvious influence on photocatalytic performance, and the optimal loading of g-C3N4 was 10 wt-%. The enhanced photocatalytic activity could be attributed to the synergetic effects of the macrochannel structure, the large specific surface area, and the heterojunction between TiO2 and g-C3N4. The main oxidative species responsible for the photodegradation of pollutants were further confirmed by the trapping experiments.

scholarly journals Preparation of Fe-DopedTiO2Nanotubes and Their Photocatalytic Activities under Visible Light

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Honghui Teng ◽  
Shukun Xu ◽  
Dandan Sun ◽  
Ying Zhang
Keyword(s):  
Visible Light ◽  
Visible Region ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Ultrasonic Assisted ◽  
Uv Visible

Fe-doped TiO2nanotubes (Fe-TNTs) have been prepared by ultrasonic-assisted hydrothermal method. The structure and composition of the as-prepared TiO2nanotubes were characterized by transmission electron microscopy, X-ray diffraction, and UV-Visible absorption spectroscopy. Their photocatalytic activities were evaluated by the degradation of MO under visible light. The UV-visible absorption spectra of the Fe-TNT showed a red shift and an enhancement of the absorption in the visible region compared to the pure TNT. The Fe-TNTs were provided with good photocatalytic activities and photostability and under visible light irradiation, and the optimum molar ratio of Ti : Fe was found to be 100 : 1 in our experiments.

Controllable Synthesis and Photocatalytic Activity of Ba0.6Mg0.4TiO3 Particles with Different Morphologies

2014 ◽  
Vol 955-959 ◽  
pp. 2267-2275 ◽  
Author(s):  
Rong Liu ◽  
Shi Duo Zhao ◽  
Xue Lin
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Hydrothermal Process ◽  
Light Irradiation ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Xrd Patterns

Ba0.6Mg0.4TiO3 (BMT) particles with different morphologies were synthesized through hydrothermal method and their optical and photocatalytic properties were investigated. Their crystal structure and microstructures were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). XRD patterns demonstrate that the as-prepared samples are tetragonal structure. FESEM shows that BMT crystals can be fabricated in different morphologies by simply manipulating the reaction parameters of hydrothermal process. The UV-visible diffuse reflectance spectra (UV-vis DRS) reveal that the band gaps of BMT photocatalysts are about 2.37 - 2.51 eV. The as-prepared BMT photocatalysts exhibite higher photocatalytic activities in the degradation of methyl orange (MO) under visible light irradiation (λ > 420 nm) compared with traditional N-doped TiO2 (N-TiO2) and pure BaTiO3 (BTO). The high photocatalytic performance of BMT photocatalysts could be attributed to the recombination restraint of the e-/h+ pairs resulting from doping of Mg2+ ions. The influence of morphologies upon the photocatalytic properties of BMT was studied. Furthermore, BMT nanowires reveal the highest photocatalytic activity. Up to 94.0% MO is decolorized after visible light irradiation for 360 min.

scholarly journals Facile Synthesis of Ag Nanowire/TiO2 and Ag Nanowire/TiO2/GO Nanocomposites for Photocatalytic Degradation of Rhodamine B

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 763
Author(s):  
Pejman Hajipour ◽  
Abbas Bahrami ◽  
Maryam Yazdan Mehr ◽  
Willem Dirk van Driel ◽  
Kouchi Zhang
Keyword(s):  
Rhodamine B ◽  
Silver Nanowires ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
Visible Absorption ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Ag Nanowire

This paper investigates the photocatalytic characteristics of Ag nanowire (AgNW)/TiO2 and AgNW/TiO2/graphene oxide (GO) nanocomposites. Samples were synthesized by the direct coating of TiO2 particles on the surface of silver nanowires. As-prepared AgNW/TiO2 and AgNW/TiO2/GO nanocomposites were characterized by electron microscopy, X-ray diffraction, UV/visible absorption spectroscopy, and infrared spectroscopy. Transmission electron microscope (TEM) images confirmed the successful deposition of TiO2 nanoparticles on the surface of AgNWs. The photocatalytic activity of synthesized nanocomposites was evaluated using Rhodamine B (RhB) in an aqueous solution as the model organic dye. Results showed that synthesized AgNW/TiO2/GO nanocomposite has superior photocatalytic activities when it comes to the decomposition of RhB.

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.

scholarly journals Enhanced Photocatalytic Activity of Powders (P25) via Calcination Treatment

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Guohong Wang ◽  
Lin Xu ◽  
Jun Zhang ◽  
Tingting Yin ◽  
Deyan Han
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Oxidation ◽  
Uv Light ◽  
Bet Surface Area ◽  
Photocatalytic Activities ◽  
Before And After ◽  
Different Temperatures ◽  
Uv Visible ◽  
Adsorption Desorption ◽  
Calcination Treatment

P25 TiO2powders were calcined at different temperatures in a muffle furnace in air. The P25 powders before and after calcination treatment were characterized with XRD FTIR, UV-visible diffuse reflectance spectra, SEM, TEM, HRTEM, and N2adsorption-desorption measurements. The photocatalytic activity was evaluated by the photocatalytic oxidation of methyl orange aqueous solution under UV light irradiation in air. The results showed that calcination treatment obviously influenced the microstructures and photocatalytic activity of the P25 TiO2powders. The synergistic effect of the phase structure, BET surface area, and crystallinity on the photocatalytic of TiO2powders (P25) after calcination was investigated. An optimal calcination temperature () was determined. The photocatalytic activity of TiO2powders calcined at was nearly 2 times higher than that of the uncalcined P25 TiO2. The highest photocatalytic activities of the calcined samples at for 4 h might be ascribed to the enhancement of anatase crystallization and the optimal mass ratio (ca. 1 : 2) of rutile to anatase.

Hydrothermal synthesis of BiVO4/Bi2MoO6 composites with enhanced photocatalytic activity

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744059 ◽  
Author(s):  
Chaoqi Xu ◽  
Hongzhi Qian ◽  
Haibo Yong ◽  
Xiaogu Huang ◽  
Wei Wang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Molar Ratio ◽  
Moderate Amount ◽  
Molar Ratios ◽  
Photocatalytic Activities ◽  
Efficient Charge ◽  
One Step ◽  
Carrier Separation ◽  
The One ◽  
Positive Effect

BiVO4/Bi2MoO6 composites have been fabricated via the one-step hydrothermal method. The properties of composites were tailored by altering the V/Mo molar ratios. Photocatalytic activities were evaluated by measuring degradation of RhB under visible-light irradiation. BiVO4/Bi2MoO6 composites with V/Mo molar ratio of 8:1 possessing the optimal photocatalytic performance. The enhanced photocatalytic activity was attributed to the efficient charge carrier separation of composite heterostructures. In addition, the study of adsorption and photocatalytic activity suggested that a moderate amount of adsorption has a positive effect on photocatalytic reaction.

Comparable Studies on Photocatalytic Activities of Ag3PO4 Microspheres and Polyhedrons

2014 ◽  
Vol 609-610 ◽  
pp. 335-340
Author(s):  
Bo Wang ◽  
Xiu Quan Gu
Keyword(s):  
Photocatalytic Activity ◽  
Surface Energy ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Chemical Method ◽  
Active Surface ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Liquid Chemical

In this study, spherical and cubic Ag3PO4 microcrystals were prepared by a facile liquid chemical method and characterized by the XRD, SEM and UV-visible spectrometry. It was found that the as-prepared Ag3PO4 cubes showed the higher photocatalytic activity and stability than the sphere under visible-light irradiation in degrading Rhodamine B (RhB). The enhanced photocatalytic activity of the Ag3PO4 polyhedron might be attributed to a higher active surface energy of the former one.

Plasmonic and non-plasmonic contributions on photocatalytic activity of Au-TiO2 thin film under mixed UV–visible light

2020 ◽  
Vol 389 ◽  
pp. 125613 ◽  
Author(s):  
Salih Veziroglu ◽  
Marie Ullrich ◽  
Majid Hussain ◽  
Jonas Drewes ◽  
Josiah Shondo ◽  
...  
Keyword(s):  
Thin Film ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Tio2 Thin Film ◽  
Uv Visible

Remarkable kinetic stability of α-thiocarbamoyl substituted 4-methoxybenzylcations

1998 ◽  
Vol 76 (12) ◽  
pp. 1910-1915 ◽  
Author(s):  
Robert A McClelland ◽  
Victoria E Licence ◽  
John P Richard ◽  
Kathleen B Williams ◽  
Shrong-Shi Lin
Keyword(s):  
Key Words ◽  
Strong Interaction ◽  
Rate Constants ◽  
Flash Photolysis ◽  
Visible Absorption ◽  
Methyl Group ◽  
Thioamide Group ◽  
Azide Ion ◽  
Uv Visible ◽  
Leaving Groups

4-Methoxybenzyl cations bearing α-(N,N-dimethylcarbamoyl) and α-(N,N-dimethylthiocarbamoyl) substituents have been generated photochemically upon irradiation of precursors with pentafluorobenzoate or 4-methoxybenzoate leaving groups. The ions have been observed with flash photolysis in 40:60 acetonitrile:water and in 50:50 methanol:water, and rate constants were measured for their decay in solvent alone and for their capture by azide ion. The cations so studied and their lifetimes in 40% acetonitrile are 6, ArC+H-CONMe2, 0.6 μs; 2, ArC+H-CSNMe2, 7 ms; and 4, ArC+(CH3)-CSMe2, 6 ms, where Ar = 4-MeOC6H4. The cation 4 reacts with solvent by elimination of a proton from the α-methyl group, and the rate constant for solvent addition must be less than 1 s-1. The CSNMe2 substituted cations are 105-107-fold longer lived than analogs where the thioamide group has been replaced with an α-methyl. The UV-visible absorption spectra of these two cations also show significant differences from those of typical 4-methoxybenzyl cations. Thus, both the lifetimes and spectra point to a strong interaction of the benzylic centre with the thioamide group. Key words: flash photolysis, thiocarbamoyl stabilized carbocation, photosolvolysis.

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