scholarly journals A Highly Efficient and Stable Photocatalyst; N-Doped ZnO/CNT Composite Thin Film Synthesized via Simple Sol-Gel Drop Coating Method

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1470
Author(s):  
Md Elias ◽  
Md Nizam Uddin ◽  
Joyanta Kumar Saha ◽  
Md Awlad Hossain ◽  
Dali R. Sarker ◽  
...  
Keyword(s):  
Thin Film ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Light Irradiation ◽  
Appreciable Change ◽  
Soda Lime Glass Substrate ◽  
Coating Method ◽  
Doped Zno

The thin film of N-doped ZnO/CNT nanocomposite was successfully fabricated on soda lime glass substrate by a simple sol-gel drop-coating method. The structural, morphological, chemical, and optical properties of as prepared samples were characterized by a variety of tools such as X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared spectroscopy (FT-IR), and UV-visible spectroscopy. The hexagonal crystalline structure was confirmed from XRD measurement without any other impurity phase detection in samples. The N-doped ZnO/CNT composite showed excellent photo-catalytic activity towards cationic methylene blue (MB) dye degradation with 100% removal rate under UV light irradiation as compared to N-doped ZnO (65%) and pure ZnO (47.36%). The convincing performance has also been observed for the case of visible light irradiation. The enhancement of that photocatalytic activity might be due to narrowing the band gap as well as the reduction of electron–hole pair recombination in ZnO matrix with the incorporation of dopant nitrogen and CNT. It is assumed from the obtained results that N-doped ZnO/CNT nanocomposite thin film can be employed as an economically achievable and ecofriendly method to degrade dye with UV and visible light irradiation. Additionally, density functional theory (DFT) calculations were applied to explore the effect of N-doping on electronic structure of ZnO. The computational study has supported the experimental results of significant band gap contraction, which leads to the maximum absorption towards higher wavelength and no appreciable change of lattice parameters after doping. A conceivable photocatalytic mechanism of N-doped ZnO/CNT nanocomposite has been proposed as well.

Effect of ZnO on a Superhydrophilic Self-Cleaning Properties of TiO2/SiO2 Thin Film on Glass Slide Substrate

2015 ◽  
Vol 1131 ◽  
pp. 237-241 ◽  
Author(s):  
Akkarat Wongkaew ◽  
Chanida Soontornkallapaki ◽  
Naritsara Amhae ◽  
Wichet Lamai
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Visible Light ◽  
Band Gap ◽  
Sol Gel ◽  
Dip Coating ◽  
Band Gap Energy ◽  
Gap Energy ◽  
Coating Method ◽  
Dip Coating Method

This work aims to study the effect of ZnO containing in TiO2/SiO2 film on the superhydrophilic property after exposed to different types of light. The metal solutions were prepared by sol-gel technique and the film was deposited on glass slides by dip coating method. The parameter studied was the amount of ZnO in the TiO2/SiO2 film. The contents of ZnO were 5-20% weight (increased by 5%). The amount of TiO2 was constant at 30% weight. The obtained films were analyzed for their roughness. The results indicated that film roughness changed according to the ZnO contents. With 5%ZnO in the thin film, the roughness was 0.726 nm while 20%ZnO obtained the roughness of 2.128 nm. UV-Vis spectrophotometer was used for measuring of transmittance of films. At wavelength of 550 nm, the transmittances of each film were greater than 90%. Band gap energy of each film was calculated from the transmittance data. It was found that the average band gap energy of the films was 2.47 eV. Then, the films contained various amount of ZnO were grouped into 2 sets. The first set was exposed to visible light while the other set was exposed to UV. The duration of exposure was 5 hr. Both sets of films after exposed to any light were kept in a black box controlled relative humidity of 85%. Each film was measured contact angle every day. It was found that the 30%TiO2/5%Zn/SiO2 film exposed to visible light showed the best superhydrophilic property. The contact angle was about 0-5° within 3 days. This may due to the reduction of band gap energy in the presence of ZnO in TiO2/SiO2 films to 2.41 eV and the roughness of the film.

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.

N-Loaded TiO2 for Photocatalytic Degradation of Methyl Orange under Visible Light Irradiation

2012 ◽  
Vol 622-623 ◽  
pp. 883-888
Author(s):  
Natkritta Boonprakob ◽  
Natda Wetchakun ◽  
Sukon Phanichphant ◽  
Jun Chen ◽  
Burapat Inceesungvorn
Keyword(s):  
Methyl Orange ◽  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Gap Energy ◽  
Visible Light Driven ◽  
Degradation Of Methyl Orange

Nitrogen-loaded TiO2(N-loaded TiO2), a visible-light driven catalyst, was successfully synthesized by the modified sol-gel method. Physical characterizations of the as-prepared catalysts have been performed by using X-ray diffraction (XRD), Diffuse reflectance UVvisspectroscopy(DRUVvis), Raman spectroscopyand BETspecific surface areain order to obtain structure-activity relationship. Results from Raman spectroscopy clearly suggested that N atoms were incorporated into the TiO2crystal lattice as evidenced by the vibrational peak of TiN in TiO2-xNx.DR UVvis results also suggested that the nitrogen dopant might be responsible for narrowing the TiO2band gap energy, thus resulting in a shift towards the visiblelight region. Photocatalytic activity of N-loaded TiO2evaluated through the degradation of methyl orange (MO)under visible light irradiation (l> 400 nm) indicated that all N-loaded photocatalysts exhibited significantly higher activities than the unloaded TiO2and Degussa P25 TiO2. According to the results from DR UV-vis, XRD and BET studies, the enhanced photoactivity observed from N-loaded samples might be due to a decrease in TiO2band gap energy and/or changes in chemical and physical properties of the materials upon loading with nitrogen.

Synthesis of nitrogen-doped ZnO by sol–gel method: characterization and its application on visible photocatalytic degradation of 2,4-D and picloram herbicides

2015 ◽  
Vol 14 (3) ◽  
pp. 536-542 ◽  
Author(s):  
J. J. Macías-Sánchez ◽  
L. Hinojosa-Reyes ◽  
A. Caballero-Quintero ◽  
W. de la Cruz ◽  
E. Ruiz-Ruiz ◽  
...  
Keyword(s):  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Zno Nanoparticles ◽  
Photocatalytic Performance ◽  
Sol Gel ◽  
Light Irradiation ◽  
Gel Method ◽  
Nitrogen Doped ◽  
Doped Zno

The photocatalytic performance of modified 30% wt. N-ZnO nanoparticles under visible light irradiation was demonstrated by the oxidation of picloram and 2,4-D.

scholarly journals Fe-doped TiO2/Kaolinite as an Antibacterial Photocatalyst under Visible Light Irradiation

2021 ◽  
Vol 16 (2) ◽  
pp. 293-301
Author(s):  
Anthoni B. Aritonang ◽  
Eka Pratiwi ◽  
Warsidah Warsidah ◽  
S. I. Nurdiansyah ◽  
R. Risko
Keyword(s):  
Visible Light ◽  
Band Gap ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Light Irradiation ◽  
Wave Number ◽  
Crystal Lattices ◽  
Doped Tio2 ◽  
Tio2 Lattice ◽  
Kaolinite Surface

In this work, undoped and Fe-doped TiO2 immobilized on kaolinite surface was successfully synthesized by sol-gel method with various Fe concentrations (0.05, 0.125, and 0.25 wt%). The effects of Fe doping into TiO2 lattice were thoroughly investigated by a diffuse reflectance UV-visible (DRS) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The optical band gap of undoped and Fe-doped TiO2/kaolinite is red shifted with respect to the incorporation of Fe3+ into the structure of TiO2 resulted band gap. The FTIR spectra shows a shift of peak at the wave number at 586 cm−1 and 774 cm−1 which is attribute of the Fe−O vibration as an indication of the formation of Fe-TiO2 bonds. Incorporation of Fe3+ cation into the TiO2 lattice replacing the Ti4+ ions, which induced a perturbation in anatase crystal structure, causes the change in the distance spacing of the crystal lattices dhkl(101) of 8.9632 to 7.9413. The enhanced photocatalytic performance was observed for Fe-doped TiO2/kaolinite compared with TiO2/kaolinite with respect to Escherichia coli growth inhibition in solution media under visible light irradiation. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).  

Cu Doped TiO2: Visible Light Assisted Photocatalytic Antimicrobial Activity and High Temperature Anatase Stability

2018 ◽  
Author(s):  
Snehamol Mathew ◽  
Priyanka Ganguly ◽  
Stephen Rhatigan ◽  
Vignesh Kumaravel ◽  
Ciara Byrne ◽  
...  
Keyword(s):  
Visible Light ◽  
Visible Light Irradiation ◽  
Density Functional ◽  
Anatase Phase ◽  
Sol Gel ◽  
Chemical Properties ◽  
Light Irradiation ◽  
Health Concern ◽  
Bacterial Inactivation ◽  
X Ray

Indoor surface contamination by microbes is a major public health concern. A damp environment is one potential sources for microbe proliferation. Smart photocatalytic coatings on building surfaces using semiconductors like titania (TiO<sub>2</sub>) can effectively curb this growing threat.<b> </b>Metal-doped titania in anatase phase has been proved as a promising candidate for energy and environmental applications. In this present work, the antimicrobial efficacy of copper (Cu) doped TiO<sub>2 </sub>(Cu-TiO<sub>2</sub>) was evaluated against <i>Escherichia coli</i> (Gram-negative) and <i>Staphylococcus aureus</i> (Gram-positive) under visible light irradiation. Doping of a minute fraction of Cu (0.5 mol %) in TiO<sub>2 </sub>was carried out <i>via</i> sol-gel technique. Cu-TiO<sub>2</sub> further calcined at various temperatures (in the range of 500 °C – 700 °C) to evaluate the thermal stability of TiO<sub>2</sub> anatase phase. The physico-chemical properties of the samples were characterised through X-ray diffraction (XRD), Raman spectroscopy, X-ray photo-electron spectroscopy (XPS) and UV-visible spectroscopy techniques. XRD results revealed that the anatase phase of TiO<sub>2</sub> was maintained well, up to 650 °C, by the Cu dopant. UV-DRS results suggested that the visible light absorption property of Cu-TiO<sub>2 </sub>was enhanced and the band gap is reduced to 2.8 eV. Density functional theory (DFT) studies emphasises the introduction of Cu<sup>+</sup> and Cu<sup>2+</sup> ions by replacing Ti<sup>4+</sup> ions in the TiO<sub>2</sub> lattice, creating oxygen vacancies. These further promoted the photocatalytic efficiency. A significantly high bacterial inactivation (99.9%) was attained in 30 mins of visible light irradiation by Cu-TiO<sub>2</sub>.

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 Photocatalytic Hydrogen Production from Glycerol Aqueous Solution Using Cu-Doped ZnO under Visible Light Irradiation

2019 ◽  
Vol 9 (13) ◽  
pp. 2741 ◽  
Author(s):  
Vincenzo Vaiano ◽  
Giuseppina Iervolino
Keyword(s):  
Hydrogen Production ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Noble Metals ◽  
Light Irradiation ◽  
Precipitation Method ◽  
Glycerol Solution ◽  
Glycerol Concentration ◽  
Photocatalytic Hydrogen Production ◽  
Doped Zno

Cu-doped ZnO photocatalysts at different Cu loadings were prepared by a precipitation method. The presence of Cu in the ZnO crystal lattice led to significant enhancement in photocatalytic activity for H2 production from an aqueous glycerol solution under visible light irradiation. The best Cu loading was found to be 1.08 mol %, which allowed achieving hydrogen production equal to 2600 μmol/L with an aqueous glycerol solution at 5 wt % initial concentration, the photocatalyst dosage equal to 1.5 g/L, and at the spontaneous pH of the solution (pH = 6). The hydrogen production rate was increased to about 4770 μmol/L by increasing the initial glycerol concentration up to 10 wt %. The obtained results evidenced that the optimized Cu-doped ZnO could be considered a suitable visible-light-active photocatalyst to be used in photocatalytic hydrogen production without the presence of noble metals in sample formulation.

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