scholarly journals Photocatalytic degradation of Dyes in Water by Analytical Reagent Grade Photocatalysts – A comparative study

2017 ◽  
Author(s):  
Dnyaneshwar R. Shinde ◽  
Popat S. Tambade ◽  
Manohar G. Chaskar ◽  
Kisan M. Gadave
Keyword(s):  
Photocatalytic Activity ◽  
Metal Oxides ◽  
Dye Degradation ◽  
Low Cost ◽  
Particle Morphology ◽  
Xrd Analysis ◽  
Solar Irradiation ◽  
Tio2 Photocatalyst ◽  
Crystalline Phases ◽  
Analytical Reagent

Abstract. In a search of low cost photocatalyst for dye degradation we have evaluated photocatalytic activity of the Analytical Reagent (AR) grade ZnO, TiO2 and SnO2. The photocatalytic activity was evaluated towards the decolourization of structurally diverse dyes such as crystal violet, basic blue and methyl red under solar irradiation and compared with benchmark Degussa P-25 (TiO2) photocatalyst. The received metal oxides were characterized by the different physicochemical methods of analysis. Powder XRD analysis showed that these metal oxides are polycrystalline in nature and crystallized in different crystalline phases. The crystalline phases of these oxides were found to be hexagonal for ZnO, tetragonal for TiO2 and rutile for SnO2. Particle morphology was analysed through SEM imaging and it showed that these oxides consists of different particle morphologies and have different particle sizes. Band gap was evaluated from diffuse reflectance spectra and it was found to be 3.24, 3.20 and 3.66 eV respectively for ZnO, TiO2 and SnO2. Among the three AR grade oxides, ZnO exhibited highest photocatalytic activity which is even higher than Degussa P-25 (TiO2) photocatalyst. About 20 % enhancement in the photocatalytic activity of AR grade ZnO was observed when silver metal loaded of on ZnO surface.

scholarly journals Photocatalytic degradation of dyes in water by analytical reagent grades ZnO, TiO<sub>2</sub> and SnO<sub>2</sub>: a comparative study

2017 ◽  
Vol 10 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Dnyaneshwar R. Shinde ◽  
Popat S. Tambade ◽  
Manohar G. Chaskar ◽  
Kisan M. Gadave
Keyword(s):  
Photocatalytic Activity ◽  
Metal Oxides ◽  
Photocatalytic Degradation ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Low Cost ◽  
Solar Irradiation ◽  
Degradation Of Dyes ◽  
Photocatalytic Activities ◽  
Analytical Reagent

Abstract. In this study, we evaluated the photocatalytic activities of analytical reagent (AR) grade ZnO, TiO2, and SnO2 to identify a low-cost photocatalyst for dye degradation. The obtained samples of ZnO, TiO2, and SnO2 were characterised by X-ray diffractogram (XRD), scanning electron microscope imaging, and UV-VIS diffuse reflectance spectroscopy. The decolourisation of three structurally diverse dyes, namely crystal violet, basic blue, and methyl red under solar irradiation, was used to evaluate the photocatalytic activities of three metal oxides. The photocatalytic activities of the received three metal oxides were tested with the photocatalytic degradation of dyes and compared with Degussa P-25. Dye solutions with each metal oxide at initial pH 9 were subjected to irradiation under sunlight and monitored for up to the stage of complete decolourisation. The results indicate that ZnO exhibited the highest photocatalytic activity as compared to TiO2 and SnO2 as well as that of Degussa P-25 (TiO2). The photocatalytic dye decolourisation rates with ZnO were 1.14–1.35, 1.70–3.1, and 4–8.5 times higher than those of the Degussa P-25, TiO2, and SnO2, respectively. The percentage COD removal was studied for ZnO and partial removal was observed at the decolourisation stage. To enhance photocatalytic activity of AR grade ZnO, it was loaded with Ag metal and about 20 % enhancement in the activity was observed.

scholarly journals Vanadium doped CaTiO3 cuboids: Role of vanadium in improving the photocatalytic activity

2021 ◽  
Author(s):  
Harsha Bantawal ◽  
Sandhya U. Shenoy ◽  
Denthaje Krishna Bhat
Keyword(s):  
Photocatalytic Activity ◽  
Water Splitting ◽  
Dye Degradation ◽  
Low Cost ◽  
Physicochemical Stability ◽  
Photocatalytic Dye Degradation

CaTiO3 has attracted enormous interest in the field of photocatalytic dye degradation and water splitting owing to its low cost, excellent physicochemical stability and structural tunability. Herein, we have developed...

Structure, morphology features and photocatalytic properties of α-Ag2WO4 nanocrystals-modified Palygorskite clay

2021 ◽  
Vol 02 ◽  
Author(s):  
Amanda Carolina Soares Jucá ◽  
Francisco Henrique Pereira Lopes ◽  
Herbert Vieira Silva-Júnior ◽  
Lara Kelly Ribeiro Silva ◽  
Elson Longo ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Rhodamine B ◽  
Dye Degradation ◽  
Degradation Kinetics ◽  
Low Cost ◽  
Catalytic Efficiency ◽  
Photocatalytic Properties ◽  
Impregnation Method ◽  
Heat Treated ◽  
Modified Palygorskite

Aims: In the present study, we investigate the photocatalytic properties of α-Ag2WO4 nanocrystals-modified Palygorskite (PAL) clay synthesized by the impregnation method. The PAL clay was chemically purified and heat-treated (500 ºC for 2 h), which served as an excellent supporting matrix for loading α-Ag2WO4(α-AWO) nanocrystals. Background: Water contamination is one of the most serious problems affecting human health, ecosystem survival, and the economic growth of societies. Industrial effluents, such as textile dyes, when not treated and improperly discharged into water resources are considered the main cause of water pollution. Thus the scientific community has been developing effective remediation technologies based on advanced oxidative processes to reduce the harmful effects of these organic pollutants. Objective: Improve the photocatalytic activity of PAL clay with α-AWO nanocrystals to degradation of Rhodamine B (RhB) dye. Methods: We purify and heat-treated the PAL clay, synthesize nanocrystals ofα-AWO nanocrystals and modify PAL clay with 30% α-AWO nanocrystals by the impregnation method. The modified PAL clay was able to improve RhB dye degradation. The materials were characterized by XRD, RAMAN,FE-SEM, FT-IR, XRF, etc. The samples were used as photocatalysts under UV-C lamps for the degradation of RhB dye in order to analyze its catalytic performances. Results: ThePAL clay modified with 30% α-AWO nanocrystals showed a catalytic efficiency of 79%, and degradation kinetics about 16 times higher when compared to PAL-500 only purified and heat-treated at 500 ºC. In this way, this PAL-modified is an alternative as a low-cost photocatalyst for the degradation of RhB dye. Conclusion: Ultraviolet-Visiblespectra revealed that our materials have opticalband gap energies controlled by indirect and direct electronic transitions and suitable to be activated under ultraviolet illumination. The adequate amount (30 wt.%) of α-Ag2WO4 nanocrystals added to PAL brought significant improvement of photocatalytic activity for the degradation of rhodamine B. Finally, a photocatalytic mechanism was proposed in detail.

Photocatalytic Water Splitting and Photocatalytic Degradation in Aqueous GdVO4 Suspensions under Simulated Solar Irradiation

2013 ◽  
Vol 873 ◽  
pp. 571-574 ◽  
Author(s):  
Yan Bai ◽  
Ya Ming Ding ◽  
Zhi Min Li
Keyword(s):  
Photocatalytic Activity ◽  
High Temperature ◽  
Solid State ◽  
Water Splitting ◽  
Rhodamine B ◽  
Pure Water ◽  
Xrd Analysis ◽  
Solar Irradiation ◽  
Tetragonal Type ◽  
Simulated Solar Irradiation

GdVO4 was synthesized by solid state reaction at high temperature and characterized by XRD, UVvisible DRS, BET and SEM. XRD analysis of GdVO4 showed its structure was of tetragonal type. When GdVO4 was loaded with 0.3 wt% Pt, it showed the better photocatalytic activity for water splitting under simulated solar irradiation, and the amounts of the produced hydrogen in pure water were about 9.33 μmol under the irradiation of simulated solar for 6 h. Furthermore, photodegradation of Rhodamine B (Rh B ) on the samples were investigated under simulated solar irradiation.

scholarly journals Improvement of the Efficiency of TiO2 Photocatalysts with Natural Dye Sensitizers Anthocyanin for the Degradation of Methylene Blue: Review

2021 ◽  
Vol 16 (2) ◽  
pp. 84-99
Author(s):  
Hendrini Pujiastuti ◽  
Indar Kustiningsih ◽  
Slamet Slamet
Keyword(s):  
Visible Light ◽  
Dye Degradation ◽  
Low Cost ◽  
Electron Excitation ◽  
Band Gap Energy ◽  
Natural Dye ◽  
Tio2 Photocatalyst ◽  
Tio2 Photocatalysts ◽  
Dye Sensitizer ◽  
Potential Methods

One of the potential methods utilized for dye degradation is photocatalitic, due to its low cost, highly effective, and environmentally friendly. Effectivenes of TiO2 photocatalysts can be enhanced by adding a dye sensitizer. Dye-sensitizer material absorbs visible light to facilitate electron excitation process. Addition of dye-sensitizer on TiO2 photocatalyst promotes it to be more responsive to visible light. Natural anthocyanin dyes are often used as sensitizers of TiO2 semiconductors. Anthocyanins are, usually in the purple to the red color range, a group of natural dyes found in the flowers, leaves, and fruit of plants. The essential principles of dye sensitization to TiO2 have been explored in this review. It is feasible to reduce the band gap energy in the TiO2 photocatalyst by modifying it using a natural dye sensitized modification. Dye sensitizers on TiO2 nanotubes plate have the potential to be employed in a dye degradation photocatalytic system

scholarly journals CdS Loaded Activated Carbon: An Efficient, Solar Light Driven Photocatalyst for RhB Dye Degradation

2019 ◽  
Vol 35 (3) ◽  
pp. 1037-1044
Author(s):  
Sagar Kande ◽  
Udhav Ghoshir ◽  
Jayshree Khedkar ◽  
Anil Gambhire
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Activated Carbon ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Dye Degradation ◽  
Xrd Analysis ◽  
Band Gap Energy ◽  
X Ray ◽  
Adsorption Desorption

A series of novel photocatalyst with CdS loaded on activated carbon (xAC/CdS) were successfully synthesized by a simple hydrothermal method. The activated carbon content was varied between 0-7 wt. %. The prepared photocatalysts were characterized by X-ray diffraction, scanning electron microscopy with EDX, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy, N2 adsorption-desorption analysis and photoluminescence spectroscopy. The photocatalytic activity of as-synthesized photocatalysts was studied for RhB dye degradation under natural sunlight irradiation. XRD analysis assigned both cubic and hexagonal morphology for xAC/CdS photocatalysts. The UV-vis DRS studies showed that loading of CdS on activated carbon enhances its visible light absorption with decrease in band gap energy. The lowest photoinduced e/h pair recombination rate in 3wt% AC/CdS results in optimum photocatalytic activity as revealed by photoluminescence study. The enhancement in dye degradation ability (̴ 11 times) of prepared photocatalysts can be attributed to synergistic effect of CdS and activated carbon.

Study on fabrication of Sn-doped ZnO thin films oriented to the application for organic dye degradation catalysts in water environment

2021 ◽  
Vol 10 (3) ◽  
pp. xx-xx
Author(s):  
Doanh Vu Viet ◽  
Trang Nguyen Thu ◽  
Kiet Le Minh ◽  
Minh Duong Quoc ◽  
Thong Trinh Quang ◽  
...  
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Dye Degradation ◽  
Sol Gel ◽  
Photocatalytic Property ◽  
Dip Coating ◽  
Solar Irradiation ◽  
Zno Films ◽  
Blue Dye ◽  
Doped Zno

In this study, zinc oxide (ZnO) doped with Sn thin films were deposited on the glass substrate at 550 °C by dip-coating technique using the solution synthesized by sol-gel method. The structural, surface morphology, optical and photocatalytic property of thin films were studied. X-ray diffraction (XRD) analysis showed that the Sn-doping greatly changed the microstructure, morphology and optical properties of ZnO films, which may contribute to the enhancement of photocatalytic activity. Additionally, the photocatalytic activity was investigated using methylene blue  dye under solar irradiation, with has high UV index from 7 to 8. The results indicated that Sn-doped ZnO had a higher photocatalytic activity and Sn dopant greatly increased the photocatalytic activity of ZnO thin film.

scholarly journals Stabilization of ZnO Nanoparticles Using Water Extract of Waste Coconut Husk and Photocatalytic Activity

2021 ◽  
Author(s):  
Sanjib Baglari ◽  
Dulu Brahma ◽  
Ujjal K Gautam ◽  
Pranjal Kalita ◽  
Manasi Buzar Baruah
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Zinc Oxide Nanoparticles ◽  
Low Cost ◽  
Water Extract ◽  
Photon Absorption ◽  
Alkaline Media ◽  
Solar Irradiation ◽  
Oxide Nanoparticles ◽  
Coconut Husk

Abstract Here, we report the synthesis of highly photoactive zinc oxide nanoparticles using water extract of waste coconut husk ash as a precipitating agent in a green approach which is a potential source of natural alkaline media. The formation of zinc oxide nanoparticles at different pH of the solution of coconut husk ash was confirmed through powder XRD, SEM-EDX, UV-Vis, FTIR and photoluminescence spectroscopy. The photocatalytic performance of the samples was evaluated through the degradation of methylene blue (MB)and methyl orange (MO) under solar irradiation which undergoes degradation around 98% and 56% within 120 min, respectively. The high photocatalytic activity and rate constant could be attributed to the large surface area due to small particle size that could provide quicker photon absorption and reduction of charge carrier recombination. This current work introduces a new method to reduce energy consumption for the synthesis of highly photoactive low-cost zinc oxide nanoparticles.

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