scholarly journals Methylene Blue Photocatalytic Degradation under Visible Irradiation on In2S3 Synthesized by Chemical Bath Deposition

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
William Vallejo ◽  
Carlos Díaz-Uribe ◽  
Kathy Rios
Keyword(s):  
Methylene Blue ◽  
Raman Spectroscopy ◽  
Photocatalytic Degradation ◽  
Chemical Bath Deposition ◽  
Visible Region ◽  
Physicochemical Characterization ◽  
Ion Source ◽  
Electromagnetic Spectrum ◽  
Visible Irradiation ◽  
Diffraction Patterns

In this work, we synthesized In2S3 powder through chemical bath deposition method (CBD) in acid medium; we used thioacetamide as sulphide source and InCl3 as indium ion source. X-ray diffraction, diffuse reflection, and Raman spectroscopy measurements were used for In2S3 powder physicochemical characterization. Optical analysis indicated that In2S3 was active in the visible region of electromagnetic spectrum; it had a band gap of 2.47 eV; the diffraction patterns and Raman spectroscopy suggested that powder had polycrystalline structure. Furthermore, we also studied the adsorption process of methylene blue (MB) on In2S3 powder; adsorption studies indicated that the Langmuir model describes experimental data. Finally, photocatalytic degradation of MB was studied under visible irradiation in aqueous solution; besides, pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation; results indicated that the powder catalyst reduces 26% concentration of MB under visible irradiation.

scholarly journals Methylene Blue Photodegradation under Visible Irradiation on Ag-Doped ZnO Thin Films

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
William Vallejo ◽  
Alvaro Cantillo ◽  
Carlos Díaz-Uribe
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Raman Spectroscopy ◽  
Photocatalytic Degradation ◽  
Physicochemical Characterization ◽  
Zno Thin Films ◽  
Visible Range ◽  
X Ray ◽  
Visible Irradiation ◽  
Doped Zno

This study synthesized and characterized Ag-doped ZnO thin films. Doped ZnO powders were synthesized using the sol-gel method, and thin films were fabricated using the doctor blade technique. The Ag content was determined by optical emission spectrometers with inductively coupled plasma (ICP plasma). Additionally, X-ray diffraction, Raman spectroscopy, Atomic Force Microscopy (AFM), diffuse reflectance, and X-ray photoelectron spectroscopy (XPS) measurements were used for physicochemical characterization. Finally, the photocatalytic degradation of methylene blue (MB) was studied under visible irradiation in aqueous solution. The Langmuir-Hinshelwood model was used to determine the reaction rate constant of the photocatalytic degradation. The physicochemical characterization showed that the samples were polycrystalline, and the diffraction signals corresponded to the ZnO wurtzite crystalline phase. Raman spectroscopy verified the ZnO doping process. The AFM analysis showed that roughness and grain size were reduced after the doping process. Furthermore, the optical results indicated that the presence of Ag improved the ZnO optical properties in the visible range, and the Ag-doped ZnO thin films had the lowest band gap value (2.95 eV). Finally, the photocatalytic degradation results indicated that the doping process enhanced the photocatalytic activity under visible irradiation, and the Ag-doped ZnO thin films had the highest MB photodegradation value (45.1%), as compared to that of the ZnO thin films (2.7%).

scholarly journals Photocatalytic Activity of Ag-TiO2 Composites Deposited by Photoreduction under UV Irradiation

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Carlos Díaz-Uribe ◽  
Jose Viloria ◽  
Lorraine Cervantes ◽  
William Vallejo ◽  
Karen Navarro ◽  
...  
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Uv Irradiation ◽  
Ag Nanoparticles ◽  
Nitrate Solution ◽  
Physicochemical Characterization ◽  
Soda Lime Glass ◽  
X Ray

In this work, we synthesized Ag nanoparticles on TiO2 thin films deposited on soda lime glass substrates. Ag nanoparticles were synthesized by photoreduction under UV irradiation silver nitrate solution. X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) measurements were used for physicochemical characterization. The structural study showed that all samples were polycrystalline, main phases were anatase and rutile, and no additional signals were detected after surface modification. Raman spectroscopy suggested that silver aggregates deposited on the TiO2 films could exhibit the surface plasmon resonance (SPR) phenomenon; XPS and SEM analysis confirmed TiO2 film morphological modification after photoreduction process. Photocatalytic degradation of methylene blue (MB) was studied under UV irradiation in aqueous solution, and, besides, pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation. Results indicated that Ag-TiO2 showed an important increase in photocatalytic activity under UV (from 20% to 35%); finally, Ag-TiO2 thin films had kapp value 2.4 × 10−3 ± 0.003 min−1 of 1.8 times greater than the kapp value 1.3 × 10−4 ± 0.0004 min−1 of TiO2 thin films.

scholarly journals Preparation of ternary ZnO/Ag/cellulose and its enhanced photocatalytic degradation property on phenol and benzene in VOCs

2019 ◽  
Vol 17 (1) ◽  
pp. 779-787 ◽  
Author(s):  
Xiao-Hang Zou ◽  
Si-Wei Zhao ◽  
Ji-Guo Zhang ◽  
Hui-Liang Sun ◽  
Qing-Jiang Pan ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Separation Efficiency ◽  
Uv Light ◽  
Low Cost ◽  
Visible Region ◽  
X Ray Diffraction ◽  
Ternary Composite ◽  
Photogenerated Electrons ◽  
Excellent Photocatalytic Activity ◽  
Diffraction Patterns

AbstractThe ZnO/Ag/cellulose composite (ZAC) with excellent photocatalytic activity of degrading benzene and phenol in VOCs has been successfully synthesized. EDS, TEM, XPS and UV-vis analyses show that the ZAC is a ternary composite. It is composed of Ag, ZnO and cellulose, where the cellulose works as the substrate to anchor the other two components. The X-ray diffraction patterns find well-crystallized ZnO nanoparticles. Multiple PL peaks in the visible region measured for ZAC, imply rich defects on ZnO. It is observed that Ag nanoparticles are mainly attached on ZnO in the composite, which would raise the separation efficiency of photogenerated electrons and holes. Photocatalytic degradation shows that ZAC is able to decompose almost 100% phenol and 19% benzene in VOCs under UV light irradiation (6 W) which is almost no harm to human body. Due to the renewable cellulose, our ternary composite ZAC imparts low-cost, easily recycled and flexible merits, which might be applied in the indoor VOCs treatment.

Syntheses of copper–iodine cluster-based frameworks for photocatalytic degradation of methylene blue

CrystEngComm ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 1232-1236 ◽  
Author(s):  
Juan Liu ◽  
Yu-Huan Tang ◽  
Fei Wang ◽  
Jian Zhang
Keyword(s):  
Methylene Blue ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Region ◽  
Blue Dye ◽  
Methylene Blue Dye

Cu–I cluster-based MOFs show a broad range of absorption in the visible region and exhibit excellent photocatalytic degradation of methylene blue dye under visible light.

scholarly journals Effect of several commercial rubber as substrates for zinc oxide in the photocatalytic degradation of methylene blue under visible irradiation

2020 ◽  
Vol 14 (9) ◽  
pp. 838-847
Author(s):  
R. Nordin ◽  
N. Latiff ◽  
R. Yusof ◽  
W. I. Nawawi ◽  
M. Z. Salihin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Zinc Oxide ◽  
Photocatalytic Degradation ◽  
Visible Irradiation

Visible light assisted photocatalytic degradation of methylene blue dye and mixture of dyes using ZrO2-TiO2 nanocomposites

2020 ◽  
Vol 16 ◽  
Author(s):  
Radhakrishna S. Sutar ◽  
Rani P. Barkul ◽  
Meghshyam K. Patil
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Anatase Phase ◽  
Physicochemical Characterization ◽  
Catalytic Efficiency ◽  
Catalyst Loading ◽  
Blue Dye ◽  
Methylene Blue Dye

Background: Different photocatalysts such as TiO2, ZnO, WO3 have been used for degradation of organic pollutants. However, these materials having some limitations, which has been affected the catalytic efficiency in the various transformations. The composites of these materials with other oxide can produce better results by tuning structural as well as optoelectrical properties. The composite of TiO2 with ZrO2 has attracted attention due to their use in different areas as ZrO2 and TiO2 have similar physicochemical features. Methods: This research contain the preparation of ZrO2-TiO2 nanocomposites by hydrothermal method and analysis of photocatalytic activity for degradation of methylene blue and mixture of dyes under visible light irradiation. Results: Physicochemical characterization of ZrO2-TiO2 nanocomposites has been studied by using different techniques. Prepared catalysts has shown anatase phase of TiO2 and tetragonal phase of ZrO2. XRD, FESEM and HRTEM have supported the nanocrystalline nature of the composites. The photocatalytic activity of composites and bare TiO2 samples were demonstrated for the degradation of methylene blue dye. Enhanced activity has been shown by composite having Ti:Zr 3:1 molar proportion i.e., Ti3Zr. Effect of concentration of methylene blue, pH of solution, catalyst loading has been studied by using Ti3Zr. Also, degradation of mixture of three dyes namely methylene blue, rhodamine B and methyl orange has been studied. Conclusion: In summary, prepared zro2-tio2 composites found to be nanocrystalline and visible light active. these catalysts has shown activity for photocatalytic degradation of methylene blue and mixture of dyes.

Photocatalytic degradation of persistent organic pollutants under visible irradiation by TiO2 catalysts sensitized with Zn(II) and Co(II) tetracarboxy-phthalocyanines

2016 ◽  
Vol 20 (08n11) ◽  
pp. 1190-1199 ◽  
Author(s):  
Yaghub Mahmiani ◽  
Altuğ Mert Sevim ◽  
Ahmet Gül
Keyword(s):  
Photocatalytic Degradation ◽  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Diffuse Reflectance Spectroscopy ◽  
Aqueous Media ◽  
Visible Region ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Visible Irradiation ◽  
The Difference

Photo-excitation under visible light has been an important step to acquire solar-driven TiO2 photocatalysts and dye sensitization has been used frequently to extend the optical response of TiO2 into the visible region. In the present work, new heterogeneous photocatalysts were prepared by anchoring carboxylic acid substituted Zn(II) and Co(II) phthalocyanines onto polycrystalline TiO2 surface and their photocatalytic activities were investigated. Due to covalent bonding of carboxy-terminated molecules onto TiO[Formula: see text]semiconductors, we synthesized symmetric 4-hydroxybenzoic acid-bearing metallophthalocyanines as dye sensitizer molecules. Heterogeneous composites having titanium dioxide and metallophthalocyanines anchored via CO–O–TiO2 bonds were characterized by using X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FT-IR), and ultraviolet-visible diffuse reflectance spectroscopy. The optimum loading value of the dyes on TiO2 were 0.98 [Formula: see text]mol/g TiO2 for CoPc and 0.86 [Formula: see text]mol/g TiO2 for ZnPc, nearly independent of the amount of TiO2 used. These newly obtained heterogeneous photocatalysts were employed in the photocatalytic degradation of 4-chlorophenol(4-CP), chlorobenzene(CB) and 1,2,4-trichlorobenzen(TCB) in aqueous media under visible irradiation. Gas chromatography-mass spectrometry (GC-MS) was used for quantitation. The new photocatalysts showed excellent activities with visible-region irradiation in the photocatalytic degradation of persistent organic pollutants (POPs) as compared to the control experiments used with untreated TiO2 and the difference was attributed to the cooperation of the two elements, namely TiO2 and MPc. Experiments show that in two hours nearly complete degradation of POPs were observed.

scholarly journals Comparative Study of ZnO Thin Films Doped with Transition Metals (Cu and Co) for Methylene Blue Photodegradation under Visible Irradiation

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 528 ◽  
Author(s):  
William Vallejo ◽  
Alvaro Cantillo ◽  
Briggitte Salazar ◽  
Carlos Diaz-Uribe ◽  
Wilkendry Ramos ◽  
...  
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Sol Gel ◽  
Physicochemical Characterization ◽  
Thin Film Deposition ◽  
Sem Analysis ◽  
Film Deposition ◽  
Morphological Properties ◽  
Visible Irradiation ◽  
Doped Zno

We synthesized and characterized both Co-doped ZnO (ZnO:Co) and Cu-doped ZnO (ZnO:Cu) thin films. The catalysts’ synthesis was carried out by the sol–gel method while the doctor blade technique was used for thin film deposition. The physicochemical characterization of the catalysts was carried out by Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction, and diffuse reflectance measurements. The photocatalytic activity was studied under visible irradiation in aqueous solution, and kinetic parameters were determined by pseudo-first-order fitting. The Raman spectra results evinced the doping process and suggested the formation of heterojunctions for both dopants. The structural diffraction patterns indicated that the catalysts were polycrystalline and demonstrated the presence of a ZnO wurtzite crystalline phase. The SEM analysis showed that the morphological properties changed significantly, the micro-aggregates disappeared, and agglomeration was reduced after modification of ZnO. The ZnO optical bandgap (3.22 eV) reduced after the doping process, these being ZnO:Co (2.39 eV) and ZnO:Co (3.01 eV). Finally, the kinetic results of methylene blue photodegradation reached 62.6% for ZnO:Co thin films and 42.5% for ZnO:Cu thin films.

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