scholarly journals Synthesis of Ag-TiO2/perlite composite for the photodegradation of methylene blue under solar light irradiation

2020 ◽  
Vol 9 (4) ◽  
pp. 42-48
Author(s):  
Nui Pham Xuan ◽  
Hoa Nguyen Thi ◽  
Tien Nguyen Trung ◽  
Tai Le Huu ◽  
Thi Tran Thi Van
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation ◽  
Adsorption Desorption

In this research, photocatalytic materials of TiO2, Ag-TiO2, Ag-TiO2/perlite were synthesized by the sol-gel method. By combining the photocatalytic activity between Ag-TiO2 and Perlite mineral, the Ag-TiO2/perlite composite has overcome the disadvantages of pristine TiO2, such as high band gap energy, low light utilization and easy recombination of electrons and holes. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherm, UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity of the samples was tested for degradation of methylene blue (MB) under solar light irradiation. Photodegradation studies revealed a 95% removal of MB dye via the synthesized Ag-TiO2/perlite after 150 min of irradiation. Reusability of this hybrid photocatalyst system was tested and only a 3% decrease was observed after four cycles.

Photocatalytic Degradation of Methylene Blue by NiO Thin Films under Solar Light Irradiation

2019 ◽  
Vol 56 ◽  
pp. 152-157 ◽  
Author(s):  
Abdelouahab Noua ◽  
Hichem Farh ◽  
Rebai Guemini ◽  
Oussama Zaoui ◽  
Tarek Diab Ounis ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Visible Region ◽  
Optical Transmittance ◽  
Dip Coating ◽  
Light Irradiation ◽  
Solar Light ◽  
Solar Light Irradiation

Nickel oxide (NiO) thin films were successfully deposited by sol-gel dip-coating method on glass substrates. The structural, morphological and optical properties in addition to the photocatalytic activity of the prepared films were investigated. The results show that the films have a polycrystalline NiO cubic structure with dense NiO grains and average optical transmittance in the visible region. The photocatalytic properties of the films were studied through the degradation of methylene blue and 89% of degradation was achieved for 4.5h of solar light irradiation exposure which indicates the capability of NiO photocatalytic activity.

Nonmetal–metal–semiconductor-promoted P/Ag/Ag2O/Ag3PO4/TiO2 photocatalyst with superior photocatalytic activity and stability

2015 ◽  
Vol 3 (34) ◽  
pp. 17858-17865 ◽  
Author(s):  
Xiaohong Hu ◽  
Qi Zhu ◽  
Xinlong Wang ◽  
Naoki Kawazoe ◽  
Yingnan Yang
Keyword(s):  
Photocatalytic Activity ◽  
Sol Gel ◽  
Light Irradiation ◽  
Solar Light ◽  
Tio2 Photocatalyst ◽  
Photocatalytic Ability ◽  
Composite Photocatalyst ◽  
Gel Method ◽  
Simulated Solar Light ◽  
Solar Light Irradiation

P/Ag/Ag2O/Ag3PO4/TiO2 composite photocatalyst has been successfully prepared by a sol–gel method. It shows highly enhanced photocatalytic ability and stability under simulated solar light irradiation.

Thickness Effect of Zno Film on the Performance of Photocatalytic in a p-Nio/n-Zno Heterostructure under Solar Light Irradiation

2020 ◽  
Vol 62 ◽  
pp. 87-95
Author(s):  
Hichem Farh ◽  
Abdelouahab Noua ◽  
Rebai Guemini ◽  
Djamal Eldine Guitoume ◽  
Oussama Zaoui
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Degradation Rate ◽  
Visible Region ◽  
Light Irradiation ◽  
Thickness Effect ◽  
Solar Light ◽  
Zno Films ◽  
Zno Film ◽  
Solar Light Irradiation

In this work, we studied the ZnO film thickness effect on the photocatalytic performance of n-ZnO/p-NiO heterostructures. The ZnO and NiO films were prepared by sol-gel dip-coating technique and the thickness of the ZnO film was varied by changing the number of coatingsfrom 2 to12. The formation of the p-NiO/n-ZnO heterostructure was confirmed by X ray diffraction (XRD). The obtained ZnO films present a wurtzite structure with a preferred orientation along (002) direction while the NiO film present a cubic structure highly oriented along (200) direction. UV-visible transmittance spectra of the prepared heterostructures revealed a good transparency in the visible region. The photocatalytic propertiesof the n-ZnO/p-NiO heterostructures were investigated by measuring the degradation rate of methylene blue. All the samples exhibit a good photocatalytic activity under solar light irradiation. The photocatalytic activity of p-NiO/n-ZnO heterostructureswas strongly correlated with the number of ZnO coatings. The highest photocatalytic activity was obtained at 6 coatings with a degradation rate of methylene blue equal to 98.67% for 4.5h of irradiation.

scholarly journals CuO@TiO2 and NiO@TiO2 core-shell catalysts for hydrogen production from the photocatalytic reforming of glycerol aqueous solution

2020 ◽  
Vol 18 (6) ◽  
pp. 390-409
Author(s):  
S. P. Ramírez ◽  
J. A. Wang ◽  
M. A. Valenzuela ◽  
L. F. Chen ◽  
A. Dalai
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Hydrogen Production ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Light Irradiation ◽  
Solar Light ◽  
Core Shell ◽  
Tio2 Catalyst ◽  
Solar Light Irradiation

Hydrogen production from the photocatalytic reforming of glycerol aqueous solution was performed on the CuO@TiO2, NiO@TiO2, NiO@CuO, and CuO@NiO core-shell nanostructured catalysts under simulated solar light irradiation. These catalysts were prepared by the combination of a modified sol-gel and a precipitation-deposition method using hydroxypropyl cellulose as structural linker and they were characterized by powder X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV–Vis DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen physisorption isotherms techniques. The catalysts containing TiO2 as a shell and CuO as core showed much higher activity compared with those formulated with NiO@CuO, CuO@NiO, and bared CuO or NiO nanoparticles. The highest rate of hydrogen production obtained with the CuO@TiO2 catalyst was as high as 153.8 μmol·g−1h-1, which was 29.0, 24.8, 11.2 and 3.2 times greater than that obtained on CuO@NiO, NiO@CuO, TiO2 P25, and NiO@TiO2 catalyst, respectively. For the high active CuO@TiO2 catalyst, after activation of TiO2 with solar light irradiation, the conduction band electrons can be transferred to CuO core through the heterojunction in the core-shell interfaces which led to CuO gradually reduced to Cu2O, favoring the reduction of proton to release hydrogen.

Comparison of the Photocatalytic Activity of N-Doped, P-Doped Titania under Solar Light Irradiation

2010 ◽  
Vol 113-116 ◽  
pp. 2141-2144
Author(s):  
Si Yao Guo ◽  
Bo Chi ◽  
Jin Bing Sun ◽  
Feng Lu Wang ◽  
Lin Yang ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Band Gap Energy ◽  
Light Irradiation ◽  
Solar Light ◽  
Urea Solution ◽  
Solar Light Irradiation ◽  
N Doping ◽  
Doped Titania ◽  
Band Gap Narrowing

P-, N-doped titania were synthesized by the direct hydrothermal method, which phosphorus from phosphoric acid and the following nitridation from urea solution. The resulting materials were characterized by XRD, XPS analysis, and their photocatalytic activities were tested by the solar light irradiation. N-doping titania resulted in the band-gap narrowing with improved photocatalytic activity. However, the phosphated titania exhibited higher photocatalytic activity than the N-doped one, but with larger band-gap energy.

scholarly journals TiO2/ZnS/CdS Nanocomposite for Hydrogen Evolution and Orange II Dye Degradation

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Václav Štengl ◽  
Daniela Králová
Keyword(s):  
Photocatalytic Activity ◽  
Band Gap ◽  
Hydrogen Evolution ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Nitrogen Adsorption ◽  
Band Gap Energy ◽  
Photocatalytic Decomposition ◽  
Orange Ii ◽  
Adsorption Desorption

TiO2/ZnS/CdS composites for photocatalytic hydrogen production from water were prepared by homogeneous hydrolysis of aqueous solutions mixture of TiOSO4, ZnSO4, and CdSO4with thioacetamide. Hydrogen evolution was observed in the presence of palladium and platinum nanoparticles deposited on TiO2/ZnS/CdS composites. The morphology was obtained by scanning electron microscopy, the nitrogen adsorption-desorption was used for determination of surface area (BET) and porosity. The method of UV-VIS diffuse reflectance spectroscopy was employed to estimate band-gap energies of prepared TiO2/ZnS/CdS nano-composites. The photocatalytic activity of the prepared samples were assessed by photocatalytic decomposition of Orange II dye in an aqueous slurry under UV irradiation at 365 nm wavelength and visible light up to 400 nm wavelength. Doped titanium dioxide by the CdS increased band-gap energy and doping with ZnS increased photocatalytic activity. The best photocatalytic activity for H2evolution shows sample named TiZnCd7 on surface deposited with palladium, which contains 20.21% TiO2, 78.5% ZnS, and 1.29% CdS.

Study on Degradation of Dyes Wastewater by N-Doped TiO2

2013 ◽  
Vol 634-638 ◽  
pp. 263-266
Author(s):  
Chao Lin Miao ◽  
Hui Wang
Keyword(s):  
Methylene Blue ◽  
Catalytic Activity ◽  
Sol Gel ◽  
Ambient Air ◽  
Light Irradiation ◽  
Photocatalytic Properties ◽  
Solar Light ◽  
Solar Light Irradiation ◽  
Degradation Of Dyes ◽  
Sol Gel Process

nano-sized TiO2 doped with different percentage of N was prepared quickly by sol-gel process，and the photocatalytic properties of degradation dyes wastewaters were studied under stimulant solar light irradiation in the ambient air. Some properties of photocatalysts were characterized by the means of XPS, UV-Vis ,XRD, and degradation loss. The results showed the catalytic activity was the best when the doped of nitrogen was 0.5% at calcinated 400°C，and the degradation of the methylene blue was almost completed.

scholarly journals Enhanced Solar Light Photocatalytic Activity of Ag Doped TiO2–Ag3PO4 Composites

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 795 ◽  
Author(s):  
Abdessalem Hamrouni ◽  
Hanen Azzouzi ◽  
Ali Rayes ◽  
Leonardo Palmisano ◽  
Riccardo Ceccato ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Environmental Remediation ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Sol Gel ◽  
Structural Features ◽  
Light Irradiation ◽  
Solar Light ◽  
Doped Tio2 ◽  
Fourier Transformed Infrared Spectroscopy

Composites comprised of Ag3PO4 and bare TiO2 (TiO2@Ag3PO4) or silver doped TiO2 (Ag@TiO2–Ag3PO4) have been synthesized by coupling sol–gel and precipitation methods. For the sake of comparison, also the bare components have been similarly prepared. All the samples have been characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), Fourier transformed infrared spectroscopy (FTIR), photoelectrochemical measurements, and specific surface area (SSA) analysis. The optoelectronic and structural features of the samples have been related to their photocatalytic activity for the degradation of 4–nitrophenol under solar and UV light irradiation. Coupling Ag3PO4 with silver doped TiO2 mitigates photocorrosion of the Ag3PO4 counterpart, and remarkably improves the photocatalytic activity under solar light irradiation with respect to the components, to the TiO2–Ag3PO4 sample, and to the benchmark TiO2 Evonik P25. These features open the route to future applications of this material in the field of environmental remediation.

scholarly journals Visible Light Induced Photodegradation of Methylene Blue in Sodium Doped Bismuth Barium Ferrite Nanoparticle Synthesized by Sol-gel Method

2018 ◽  
Vol 5 (2) ◽  
pp. 120-126 ◽  
Author(s):  
Abdurrashid Haruna ◽  
Ibrahim Abdulkadir ◽  
Suleiman Ola Idris
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Light Irradiation ◽  
Blue Dye ◽  
Gel Method ◽  
Sol Gel Method

Perovskite-like BiFeO3 nanoparticles doped with barium and sodium ions were synthesized via the citric acid route by the sol-gel method. The as-prepared Bi0.65Na0.2Ba0.15FeO3 nanopowders were divided into three equal portions and separately annealed at various annealing temperatures of 600, 700 and 800°C. The powders were characterized using X-ray diffraction (XRD) and crystallized with a rhombohedral R3c space group. Scanning electron microscopy was used to determine the morphology of the crystal and Fourier transform infrared spectroscopy was conducted at room temperature to determine the phase purity and the B-site formation in the perovskite structure. The UV-vis diffuse reflectance spectroscopy of all the materials was investigated, showing strong photoabsorption (λ > 420 nm). The doping effect of BiFeO3 enhanced photocatalytic activity while it significantly reduced the energy bandgap to 2.05 eV (for BNBFO at 800°C) which showed strong visible light absorption. The photocatalytic activity of Bi0.65Na0.2Ba0.15FeO3 nanomaterials was tested by monitoring the degradation rate of methylene blue dye pollutant under visible light irradiation in aqueous solution. All powders showed photoactivity after 2 hours of visible light irradiation. The annealing temperature greatly affected the methylene blue degradation, showing the efficiencies of 57, 67 and 75 % for BNBFO at 600, 700 and 800°C, respectively. Kinetic studies were carried out and the rate constants of 6.70 x 10-3, 8.90 x 10-3 and 1.05 x 10-2 min-1 were obtained for powders annealed at 600, 700 and 800°C, respectively. The photocatalytic mechanism of the degradation process was proposed in this study.

Photocatalytic Degradation of Methylene Blue over Co-Ag3VO4 under Visible Light Irradiation

2011 ◽  
Vol 335-336 ◽  
pp. 1385-1390 ◽  
Author(s):  
Shuo Wiei Zhao ◽  
Hui Xu ◽  
Hua Ming Li ◽  
Yuan Guo Xu
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Absorption Edge ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Light Irradiation ◽  
Experimental Conditions ◽  
X Ray

In order to improve the photocatalytic activity, Co was successfully loaded into Ag3VO4 by using impregnation process. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS) and diffuse reflectance spectroscopy (DRS). The XRD and SEM–EDS analyses revealed that Co ion was dispersed on Ag3VO4. The DRS results indicated that the absorption edge of the Co–Ag3VO4 catalyst shifted to longer wavelength. The enhanced photocatalytic activity of Co–Ag3VO4 for Methylene Blue(MB) dye degradation under visible light irradiation was due to its wider absorption edge and higher separation rate of photo-generated electron and holes. In the experimental conditions, it is demonstrated that the MB was effectively degraded by more than 95% within 40 min when the Co–Ag3VO4 catalyst was calcined at 300°C with 1 wt.% Co content.

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