scholarly journals Effect of Annealing Temperature on The Improved Photo Catalytic Degradation of Zinc Sulfide Thin Films Under Visible Light Irradiation

2020 ◽  
Vol 9 (1) ◽  
pp. 237-241
Keyword(s):  
Thin Films ◽  
Visible Light ◽  
Zinc Sulfide ◽  
Visible Light Irradiation ◽  
Annealing Temperature ◽  
Dye Degradation ◽  
Sol Gel ◽  
Light Irradiation ◽  
Atmospheric Environment ◽  
Blue Dye

Here, we reported a modern sort of zinc sulfide thin films as a catalyst was prepared from simple sol-gel approach. The as-deposited samples were further annealed at 200, 300, 4000 C temperatures under atmospheric environment. The variation in the annealing temperature becomes crucial for optimizing the prepared samples characterization and dye degradation behavior. Structural and morphological analysis recommends that test were hexagonal crystal structure and spherical shaped morphology, particle size was found within the range of 25-40 nm. The significant red shift was found within the absorption edge and lessening of energy in the band gap was found whereas the annealing temperature is increased from 200 to 400 oC. Recombination of photo-generated electron-hole sets was moreover distinguished and the photo-degradation test was monitored methylene blue dye solutions under visible light irradiation. The 400 oC annealed sample showed superior photocatalytic performance such as high degradation efficiency and long term stability towards MB dye.

Treatment of textile wastewater under visible LED lamps using CuO/ZnO nanoparticles immobilized on scoria rocks

RSC Advances ◽  
2015 ◽  
Vol 5 (92) ◽  
pp. 75474-75482 ◽  
Author(s):  
F. Mahdizadeh ◽  
S. Aber
Keyword(s):  
Thin Films ◽  
Water Treatment ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Textile Wastewater ◽  
Light Irradiation ◽  
Direct Crystallization ◽  
Crystallization Method

ZnO and CuO thin films were synthesized by a sol–gel and direct crystallization method on granular porous natural scoria respectively and CuO/ZnO/scoria was used for water treatment under visible light irradiation.

Preparation and characterization of SiO2/BiOX (X = Cl, Br, I) films with high visible-light activity

RSC Advances ◽  
2015 ◽  
Vol 5 (7) ◽  
pp. 4918-4925 ◽  
Author(s):  
Fan Shen ◽  
Li Zhou ◽  
Jiajia Shi ◽  
Mingyang Xing ◽  
Jinlong Zhang
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Visible Light Irradiation ◽  
Sol Gel ◽  
Layered Structures ◽  
Light Irradiation ◽  
Gel Method ◽  
Light Activity

SiO2/BiOX (X = Cl, Br, I) thin films with layered structures were prepared using a convenient sol–gel method. The films show a high and stable photocatalytic activity under visible-light irradiation.

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.

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>.

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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