scholarly journals Degradation of Methylene Blue Dye in the Presence of Visible Light Using SiO2@α-Fe2O3 Nanocomposites Deposited on SnS2 Flowers

Author(s):  
Sridharan Balu ◽  
Kasimayan Uma ◽  
Guan-Ting Pan ◽  
Thomas C.-K. Yang ◽  
Sayee Kannan Ramaraj

Semiconductor materials have been shown to have better photocatalytic behavior and can be utilized for the photodegradation of organic pollutants. In this work, three-dimensional flower-like SnS2 were synthesized by a facile hydrothermal method. Core-shell structured SiO2@α-Fe2O3 nanocomposites were then deposited on the top of the SnS2 flowers. The as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) and photoluminescence spectroscopy (PL). The photocatalytic behavior of the SnS2-SiO2@α-Fe2O3 nanocomposites was observed by observing the degradation of methylene blue (MB). The results show an effective enhancement of photocatalytic activity for the degradation of MB especially for the 15 wt. % SiO2@α-Fe2O3 nanocomposites on SnS2 flowers.

2014 ◽  
Vol 970 ◽  
pp. 29-32 ◽  
Author(s):  
Pongsaton Amornpitoksuk ◽  
Sumetha Suwanboon

The co-effect of PO43- and I- on the formation of a heterosturucture photocatalyst in the Ag3PO4-AgI system was studied by the co-precipitation method between AgNO3 and the precipitating agent. The precipitating agent was prepared by varying the mole ratios between Na2HPO4 and KI. At 10 mol.% KI, the product showed the mixed phase between Ag3PO4 and un-identified phase. For 30 - 90 mol.% KI, the un-identified phase and AgI were detected in the x-ray diffraction patterns. The un-identified phase strongly adsorbed the methylene blue dye. The product prepared from 30 mol.% KI had the highest content of un-identified phase and also showed the highest degree of decolorization in the dark. The photocatalytic properties of products in this system were confirmed by the decolorization of methylene blue under visible illumination.


2020 ◽  
Vol 52 (4) ◽  
pp. 415-432
Author(s):  
Faezeh Parast ◽  
Mehdi Montazeri-Pour ◽  
Masoud Rajabi ◽  
Fatemeh Bavarsiha

In the present research, Fe3O4/TiO2 magnetic photo-catalytic nanocomposites with a core/shell structure were successfully synthesized using two techniques of ultrasonic and St?ber. In this way, iron oxide (II, III) nanoparticles as soft magnetic cores of this composite were prepared by utilizing a chemical method assisted by ultrasound with a Fe+3/Fe+2 molar ratio of 1.5 under the nitrogen atmosphere. Thereafter, titanium oxide coating was performed on Fe3O4 nanoparticles by using tetrabutyl orthotitanate (TBOT) and titanium isopropoxide (TTIP) precursors. The resultant nanostructures were characterized by means of X-ray powder diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, energy dispersive X-ray (EDX) analysis, vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Through findings obtained from TEM examinations, the formation of core/shell nanostructure was confirmed in the prepared Fe3O4/TiO2 composites. Analysis of magnetic properties revealed that titanium oxide coating on iron oxide nanoparticles reduces saturation magnetization (Ms). The values of saturation magnetization for Fe3O4 powder and Fe3O4/TiO2 nanocomposite powders achieved via ultrasonic and St?ber methods were 60, 23 and 9 emu/g, respectively. Photo-catalytic properties of Fe3O4/TiO2 nanostructures were evaluated by the use of methylene blue dye under UV light. Results indicated that Fe3O4/TiO2 composite obtained by the St?ber method has a better photo-catalytic property as well as a decreased but acceptable magnetic separation. Degradation of methylene blue dye in the presence of photo-catalytic powder prepared by ultrasonic and St?ber procedures was 61 and 69 %, respectively, within 90 minutes of UV light exposure.


2010 ◽  
Vol 10 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Aarti Ameta ◽  
Indu Bhati ◽  
Rakshit Ameta ◽  
Suresh C. Ameta

The photocatalytic degradation of methylene blue dye under visible light has been investigated using chromium modified titanium dioxide supported on zeolite (Cr-TiO2/zeolite). The photocatalyst was prepared by sol-gel method and characterized by X-ray diffraction and SEM. The rate of photodegradation of dye was monitored spectrophotometrically. The effect of pH, dye concentration, amount of photocatalyst and intensity of light on the rate of photocatalytic reaction was observed. The results showed that the use of Cr-doped TiO2 increased the rate of photocatalytic degradation of methylene blue as compared to untreated TiO2. The photocatalytic mechanism of Cr-TiO2 catalyst has been tentatively discussed.   Keywords: Methylene blue, zeolite, chromium, photocatalytic degradation


2020 ◽  
Vol 17 (3) ◽  
pp. 29-40
Author(s):  
Shreyas Dindorkar ◽  
Jaymin Mistry ◽  
Jayesh Hire ◽  
Khushi Jain ◽  
Nandini Khona ◽  
...  

Herein we report the synthesis of graphene oxide-based agar composites using a solution casting method. Graphene oxide was synthesized by modified Hummer’s method and was characterized using X-ray diffraction (XRD) and Raman spectroscopy. The graphene oxide-based agar composites were characterized using X-ray diffraction (XRD) and UV-visible spectroscopy. Optical band gap obtained from the Tauc plot showed that the composites could be used in the photodegradation of dyes. The synthesized composite material was checked for its practical applicability in the degradation of methylene blue dye under solar irradiation; with an increase in the concentration of graphene oxide, catalyst, and H2O2, the rate constant increases. The rate constant was found to be inversely proportional to the concentration of methylene blue dye. Dosage of graphene oxide was found to be the most prominent factor in increasing the rate of photodegradation. It is clear from the data for the reaction system that the degradation reaction follows pseudo-first-order kinetics. Keywords: Composites; Ultra-sonication; Photodegradation; Methylene Blue; XRD; Graphene Oxide; Kinetics; Biocompatibility


2013 ◽  
Vol 448-453 ◽  
pp. 730-733
Author(s):  
Si Liang Li ◽  
Ya Jie Guo ◽  
Jing Juan Pu

A novel three-dimensional MnO2 catalyst have been successfully prepared by a facile hydrothermal route. They were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, they showed excellent catalytic activity over the aqueous degradation of methylene blue (MB).


2011 ◽  
Vol 335-336 ◽  
pp. 1508-1511
Author(s):  
Shu Kai Zheng

Transparent TiO2 thin films were deposited onto microscope glass slides by means of d.c. magnetron sputtering method. In order to enhance the photocatalytic activity of TiO2 thin films, Mo ions with different nominal doses were implanted into the TiO2 thin films. The samples were characterized by different technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS) and UV-VIS-NIR spectrophotometer. The photodegradation results of methylene blue dye solution indicated that optimal dose of 2×1012ions/cm2 Mo ion-implantation resulted in a higher photocatalytic activity in the implanted TiO2 thin films.


2013 ◽  
Vol 838-841 ◽  
pp. 2310-2313
Author(s):  
Jin Yun Liao ◽  
Hao Li

In this study, CuO microspheres were synthesized by a facile hydrothermal method. X-ray diffraction pattern indicated that the as-prepared CuO sample is presented in monoclinic phase and field emission scanning electron microscope images demonstrated that CuO were composed of CuO nanoplatelets. The catalytic activity of CuO microspheres in the degradation of methylene blue (MB) with H2O2 was investigated. It was found that the degradation ratio of MB was less than 7% in the absence of CuO catalyst, while the degradation ratio can reach about 88% in the presence of CuO catalysts. It was revealed that the degradation efficiency of MB was the highest when the dose of CuO catalysts was 20 mg.


2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.


2014 ◽  
Vol 608 ◽  
pp. 224-229 ◽  
Author(s):  
Potjanaporn Chaengchawi ◽  
Karn Serivalsatit ◽  
Pornapa Sujaridworakun

A visible-light responsive CdS/ZnO nanocomposite photocatalyst was successfully synthesized by precipitation of CdS nanoparticles, using Cd (NO3)2 and Na2S as starting materials, on ZnO nanoparticles and then calcined at 400°C for 2 hours. The effects of the mole ratio of CdS and ZnO in the composites on their phase, morphology, and surface area were investigated by X-ray Diffraction (XRD), scanning electron microscope (SEM), Brunauer Emmett Teller method (BET), respectively. The photocatalytic degradation of methylene blue solution in the presence of composite products under visible-light irradiation was investigated. The results showed that the mole ratio of CdS and ZnO played a significant role on photocatalytic performance. The highest photocatalytic activity was obtained from the CdS/ZnO nanocomposite with mole ratio of 1:4, which is higher than that of pure CdS and pure ZnO.


2020 ◽  
Vol 8 (2) ◽  
pp. 84-89
Author(s):  
Noor Hindryawati ◽  
Aman Sentosa Panggabean ◽  
Dirgarini Julia Nurlianti Subagyono ◽  
Rinda Anisyah Putri ◽  
Prilianda Kusmiaty ◽  
...  

Degradation of blue dye waste in Sarong Samarinda production using WO3-bleaching earth (BE) has been conducted. Structural and morphological characterization has conducted using X-ray diffraction (XRD), and Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). The X-ray diffraction results show the mineral on bleaching earth is rectorite dioctahedral mica layer and dioctahedral smectite with a ratio 2:1. The WO3 pattern is appeared after the calcination. After calcination at 500°C, the WO3 is deposited homogeneously on the BE surface. The catalytic performance of WO3-BE for photodegradation of the blue dye waste under the solar light is 99.85 % within 1 h.


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