Direct Sunlight Active Sm3+ Doped TiO2 Photocatalyst

2016 ◽  
Vol 855 ◽  
pp. 33-44 ◽  
Author(s):  
Binu Naufal ◽  
P.K. Jaseela ◽  
Pradeepan Periyat
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Uv Light ◽  
Sol Gel ◽  
Visible Region ◽  
Light Irradiation ◽  
Significant Shift ◽  
Sem Images ◽  
Blue Solution

TiO2 and Sm3+ doped TiO2 nanocrystalline has been successfully synthesized by a modified sol-gel method. As synthesized samples of TiO2 and Sm3+ doped TiO2 were calcined at 300, 500, 700 and 800OC and characterized by various techniques such as XRD, UV/Vis Reflectance spectroscopy, FTIR, SEM-EDS and TEM. The crystallite size of Sm3+ doped TiO2 at all calcination temperature is lower than that of TiO2 due the doping Sm3+ ion and thereby induced more nanobehavior. FTIR spectroscopy confirmed the presence of Ti-O and Ti-O-Ti bond in TiO2, in Sm3+ doped TiO2 along with Ti-O and Ti-O-Ti, the presence Sm-O and Ti-O-Sm bonds are confirmed. Diffuse reflectance spectra showed that the Sm3+ doped TiO2 have a significant shift to longer wavelengths and an extension of the absorption in the visible region compared to the TiO2. SEM images confirmed that the particles are agglomerated and the particle size was decreased in the Sm3+ doped TiO2 in comparison with the TiO2. EDS analysis showed the presence of Sm3+ ion present in the lattice of TiO2 in doped sample. Finally the photocatalytic activity of TiO2 and Sm3+ doped TiO2 at various calcinations temperatures was investigated by the degradation of methylene blue solution under UV light and visible light. Doping with the samarium ions significantly enhanced the overall photocatalytic activity for MB degradation under both UV and visible light irradiation. The results showed that the Sm3+ doped TiO2 sample calcined at 700 OC shows the highest photocatalytic activity under UV light and visible light irradiation.

Visible Light Driven Photocatalytic Hydrogen Evolution by Lanthanum and Carbon-co-Doped NaTaO3 Photocatalyst

2015 ◽  
Vol 659 ◽  
pp. 231-236 ◽  
Author(s):  
Husni Husin ◽  
Mahidin ◽  
Zuhra ◽  
Fikri Hasfita ◽  
Yunardi
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Hydrogen Evolution ◽  
Visible Light Irradiation ◽  
Absorption Edge ◽  
Sol Gel ◽  
Green Energy ◽  
Light Irradiation ◽  
Sem Images ◽  
Co Doped

Lanthanum and carbon co-doped sodium tantalum oxide, La-C-NaTaO3, are prepared by incorporating lanthanum and carbon into NaTaO3 cluster via a sol-gel technique using a sucrose as carbon source. The La-C-NaTaO3 prepared sample is calcined at a temperature of 700 °C. Effects of carbon contents on the crystal, shape, optical absorption response and activity of hydrogen production of the sample are evaluated. The crystal of La-C-NaTaO3 is characterized by XRD analysis. The results show that the XRD pattern of the La C co-doped NaTaO3 is found to be crystalline phase with monoclinic structure. From the analysis of SEM images, the particle size of the prepared powder is about 40-200 nm. The optical response is examined by diffuse reflectance spectra (DRS). It is depicted that the absorption edge of La-C-NaTaO3 crystalline shift to higher wavelength. The extension to the visible light absorption edge became drastic with increasing carbon content in the sample. The photocatalytic activity of La-C-NaTaO3 is examined from water-methanol aqueous solution under visible light irradiation. It is found that the photocatalytic activity of La-C-NaTaO3 depend strongly on the doping content of C, and sample La-C-NaTaO3 shows the highest photocatalytic activity for the water reduction. The optimum amounts of carbon to maximize the hydrogen evolution rate is to be 2.5 mol %. The La-C-NaTaO3 catalyst has high activity of H2 evolution of 40.0 [μmol h-1] and long time stability under visible-light irradiation, suggesting a promising utilization of such photocatalyst. La C co-doped NaTaO3 photocatalyst can be developed further in order to produce hydrogen as a green energy.

scholarly journals SOLVOTHERMAL SYNTHESIS OF BI2WO6 AND ITS PHOTOCATALYTIC ACTIVITY UNDER VISIBLE LIGHT IRRADIATION

2018 ◽  
Vol 54 (4B) ◽  
pp. 42
Author(s):  
Trinh Duy Nguyen
Keyword(s):  
Absorption Spectrum ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Visible Region ◽  
High Photocatalytic Activity ◽  
Light Irradiation ◽  
Different Temperatures

Flower-like Bi2WO6 were successfully synthesized using the solvothermal method at different temperatures and characterized by XRD, FE-SEM, and DRS. We also investigated the photocatalytic activity of Bi2WO6 for the decomposition of rhodamine B under visible light irradiation. From XRD and SEM results, the reaction temperature has significant effects on the morphologies of the samples. From DRS results, Bi2WO6 samples displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation, as a comparison with TiO2-P25.

scholarly journals Visible-enhanced photocatalytic performance of CuWO4/WO3 hetero-structures: incorporation of plasmonic Ag nanostructures

2018 ◽  
Vol 42 (13) ◽  
pp. 11109-11116 ◽  
Author(s):  
R. Salimi ◽  
A. A. Sabbagh Alvani ◽  
N. Naseri ◽  
S. F. Du ◽  
D. Poelman
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Light Irradiation ◽  
Photo Degradation ◽  
Gel Method ◽  
Sol Gel Method

A new plasmonic Ag hybridized CuWO4/WO3 heterostructured nanocomposite was successfully synthesized via a ligand-assisted sol gel method and the photocatalytic activity was evaluated by photo-degradation of methylene blue (MB) under visible light irradiation.

scholarly journals BiOCl/TiO2/diatomite composites with enhanced visible-light photocatalytic activity for the degradation of rhodamine B

2019 ◽  
Vol 10 ◽  
pp. 1412-1422 ◽  
Author(s):  
Minlin Ao ◽  
Kun Liu ◽  
Xuekun Tang ◽  
Zishun Li ◽  
Qian Peng ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Rhodamine B ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Light Irradiation ◽  
Molar Ratio ◽  
Visible Light Photocatalytic Activity ◽  
Visible Light Photocatalytic

A BiOCl/TiO2/diatomite (BTD) composite was synthesized via a modified sol–gel method and precipitation/calcination method for application as a photocatalyst and shows promise for degradation of organic pollutants in wastewater upon visible-light irradiation. In the composite, diatomite was used as a carrier to support a layer of titanium dioxide (TiO2) nanoparticles and bismuth oxychloride (BiOCl) nanosheets. The results show that TiO2 nanoparticles and BiOCl nanosheets uniformly cover the surface of diatomite and bring TiO2 and BiOCl into close proximity. Rhodamine B was used as the target degradation product and visible light (λ > 400 nm) was used as the light source for the evaluation of the photocatalytic properties of the prepared BTD composite. The results show that the catalytic performance of the BTD composite under visible-light irradiation is much higher than that of TiO2 or BiOCl alone. When the molar ratio of BiOCl to TiO2 is 1:1 and the calcination temperature is 400 °C, the composite was found to exhibit the best catalytic effect. Through the study of the photocatalytic mechanism, it is shown that the strong visible-light photocatalytic activity of the BTD composite results mainly from the quick migration of photoelectrons from the conduction band of TiO2/diatomite to the surface of BiOCl, which promotes the separation effect and reduces the recombination rate of the photoelectron–hole pair. Due to the excellent catalytic performance, the BTD composite shows great potential for wide application in the field of sewage treatment driven by solar energy.

Characteristics and Photocatalytic Activity of TiO2 Thin Film Sensitized with a Porphyrin Dye

2008 ◽  
Vol 8 (5) ◽  
pp. 2699-2702 ◽  
Author(s):  
K. S. Yao ◽  
D. Y. Wang ◽  
C. Y. Chang ◽  
W. Y. Ho ◽  
L. Y. Yang
Keyword(s):  
Thin Film ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Indigo Carmine ◽  
Erwinia Carotovora ◽  
Visible Spectral Region ◽  
Plant Diseases ◽  
Light Irradiation

In this study, a novel porphyrin dye, 5, 10, 15, 20-tetraphenyl-21H, 23H-porphine nickel (TPPN) doped TiO2 (TiO2/TPPN) thin film with visible light respondency was prepared using a sol–gel method and characterized with XRD, SEM, UV-Vis instruments. The observation showed that the absorption edge of TPPN dye-doped thin film shifted into the visible light region. The photocatalytic indigo carmine degradation results showed that under visible light irradiation (λ > 400 nm) for 6 hrs, the photocatalytic activity of TiO2 thin film sensitized with 200 μM of TPPN dye showed the best performance, with an indigo degradation ratio up to 96%. Moreover, the TiO2/TPPN thin film showed a relevant photocatalytic bactericidal effect on Erwinia carotovora subsp. carotovora 7 induced vegetable soft rot disease in the visible spectral region. Evidence for the photocatalytic disinfection technique against a plant pathogen under visible light irradiation will have potential for direct application in future control of plant diseases in irrigation water systems.

CdS/TiO2 composite films for methylene blue photodecomposition under visible light irradiation and non-photocorrosion of cadmium sulfide

2014 ◽  
Vol 68 (9) ◽  
Author(s):  
María Hernández-Torres ◽  
María Ojeda-Carrera ◽  
Manuel Sánchez-Cantú ◽  
Nicolás Silva-González ◽  
Justo Gracia-Jiménez
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Cadmium Sulfide ◽  
Visible Light Irradiation ◽  
Deposition Time ◽  
Sol Gel ◽  
Composite Films ◽  
Light Irradiation ◽  
Visible Range ◽  
Sem Images

AbstractCadmium sulfide/titanium dioxide (CdS/TiO2) composite films were grown on glass by the chemical bath deposition (DBQ) and sol-gel/dip coating methods, respectively, in order to increase the photocatalytic activity of TiO2 in photodegradation processes. The influence of the CdS deposition time on the morphology, optical absorption, and phononic modes of the composites were examined. Scanning electron microscopy (SEM) images showed clearly the CdS deposit on the TiO2 surface. The absorbance spectra indicated that the absorption of composites depends on the CdS deposition time and the absorption edges are shifted to the visible range. Micro Raman spectra exhibited the phonons associated with the TiO2 anatase and the longitudinal optic (LO) phonon of CdS whose intensity increases with the CdS deposition time. Photodegradation of methylene blue (MB) under visible light irradiation was observed in all films and the results were compared with those obtained with TiO2 films. The decomposition is higher for the composite with the CdS deposition time of 15 min. This optimal deposition time allows maximal enhancement of the charge carriers transfer to TiO2 involved in the photocatalysis. No signal associated with cadmium was detected by the atomic absorption spectroscopy (AAS), which means that the CdS photocorrosion does not occur since trap centers such as OH-Cd-S and Cl−, which trap holes and inhibit the photocorrosion, are produced during the growth process.

Construction of ZnxCd1−xS/CeO2 composites for enhanced photocatalytic activity and stability by chemical precipitation method

2021 ◽  
pp. 2150334
Author(s):  
Yi-Feng Chai ◽  
Zhong-Hua Zhu ◽  
Ming-Wei Liu ◽  
Jing Zeng ◽  
Gui-Fang Huang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Methyl Orange ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Uv Light ◽  
Chemical Precipitation ◽  
Charge Carriers ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Uv Light Irradiation

Development photoinduced photocatalysts is a significant approach to improve photocatalytic activity and stability. Herein, we successfully prepared Zn[Formula: see text]Cd[Formula: see text]S/CeO2 composites by a facile method. It is found that the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 composites show significant enhancement in photocatalytic activity for methyl orange (MO) degradation under visible and UV light irradiation. The degradation efficiency reaches up to 3.7 times higher than that of pure CeO2 under visible light irradiation. Moreover, the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 samples have almost no loss of photocatalytic activity after five recycles, indicating good photocatalytic stability of the samples. The attractive photocatalytic activity of the Zn[Formula: see text]Cd[Formula: see text]S/CeO2 samples could be attributed to the robust charge carriers transfer and separation.

Synthesis of MFeO3/SBA–15 (M=La or Bi) for peroxymonosulfate activation towards enhanced photocatalytic activity

2021 ◽  
Author(s):  
Di Li ◽  
Qianqian Zhao ◽  
Mingyang Long ◽  
Hongmiao Li ◽  
Qi Wen
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Light Irradiation ◽  
Sol Gel Process

MFeO3 (M=La or Bi) photocatalysts were synthesized via sol–gel process. MFeO3 photocatalysts showed lower photocatalytic activity for the degradation of doxycycline hydrochloride under visible light irradiation. After the MFeO3 nanoparticles...

scholarly journals Synthesis, Characterization, and Evaluation of Boron-Doped Iron Oxides for the Photocatalytic Degradation of Atrazine under Visible Light

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Shan Hu ◽  
Guanglong Liu ◽  
Duanwei Zhu ◽  
Chao Chen ◽  
Shuijiao Liao
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Iron Oxides ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Bet Surface Area ◽  
Boron Doped

Photocatalytic degradation of atrazine by boron-doped iron oxides under visible light irradiation was investigated. In this work, boron-doped goethite and hematite were successfully prepared by sol-gel method with trimethylborate as boron precursor. The powders were characterized by XRD, UV-vis diffuse reflectance spectra, and porosimetry analysis. The results showed that boron doping could influence the crystal structure, enlarge the BET surface area, improve light absorption ability, and narrow their band-gap energy. The photocatalytic activity of B-doped iron oxides was evaluated in the degradation of atrazine under the visible light irradiation, and B-doped iron oxides showed higher atrazine degradation rate than that of pristine iron oxides. Particularly, B-doped goethite exhibited better photocatalytic activity than B-doped hematite.

ELECTRONIC STRUCTURES OF S-DOPED ANATASE AND RUTILE TiO2

2007 ◽  
Vol 06 (01) ◽  
pp. 23-32 ◽  
Author(s):  
XIN-GUO MA ◽  
CHAO-QUN TANG ◽  
XIAO-HUA YANG
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Valence Band ◽  
Visible Light Irradiation ◽  
Electronic Structures ◽  
Density Functional ◽  
Visible Region ◽  
Light Irradiation ◽  
Band Shift ◽  
Deep Impurity

The electronic structures of S -doped TiO 2 have been carried out by first-principles calculations based on density functional theory with plane-wave ultrasoft pseudopotential method. Comparing anion doping with cation doping in anatase and rutile, we found different energy band structures and origins of photoactivity of S -doped TiO 2. For anion-doped TiO 2, new S –3p bands appear and which lie slightly above the top of the O –2p valence band. It plays a significant role in increasing absorbance in the visible region, resulting in improvement in photocatalytic activity under visible-light irradiation. For cation-doped TiO 2, the potential of the O –2p valence band shift much downwards, yielding the stronger oxidative power than that of undoped and S anion-doped TiO 2. Nevertheless, the deep impurity states in BG (bond gap) that originate from the S -dopant have negative effects on the recombination of the photoexcited electrons and holes. From our calculated results, we can explain their differences in photocatalytic activity under visible-light irradiation.

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