Synthesis and Characterization of Attapulgite Clay Coated Ag/AgBr/TiO2 Visible Light Photocatalyst

2010 ◽  
Vol 178 ◽  
pp. 285-290 ◽  
Author(s):  
Xu Gu ◽  
Jin Long Jiang ◽  
Dong Li

Attapulgite clay coated Ag/AgBr/TiO2 visible light photocatalyst was prepared by an impregnation-deposition-precipitation method. The catalyst was characterized via powder X-ray diffraction (XRD), TEM, UV-Vis spectroscopy, and EMAX, and their photocatalytic activity was examined by degradation of methylene blue in water under sunlight. The results showed that the catalyst exhibited high efficiency for the degradation of methylene blue and the catalyst activity maintained effectively after successive cyclic experiments under sunlight, attributed to adsorption of dye on attapulgite clay and high dispersion of AgBr and TiO2 nano-sized particles on the surface of attapulgite clay.

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.


2011 ◽  
Vol 117-119 ◽  
pp. 1088-1091
Author(s):  
Wen Churng Lin ◽  
Rui Liu ◽  
Wein Duo Yang

Iron-doped TiO2 photocatalyst powders were prepared by the sol–gel method and characterized by Brunauer–Emmett–Teller (BET)-specific surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Ultraviolet–Visible (UV-Vis) spectroscopy. Fe3+ doping in the TiO2 decreases the crystal grain size, increases the specific surface areas of powders, extends the absorption to visible light regions (400~500 nm), and lowers the photocatalytic activity for methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB in water was investigated as a function of the Fe3+ content in TiO2. It was found that under the irradiation of visible light, a small amount of Fe3+ dopant in TiO22 powders could obviously enhance the photocatalytic activity. When the Fe3+ content was in the range of 0.03–0.1 mol%, the photocatalytic activity of the samples was higher than that of undoped TiO2. Appropriate content of Fe-doping is an effective means to improve the photocatalytic activity of TiO2 for MB degradation under visible light irradiation.


2017 ◽  
Vol 751 ◽  
pp. 807-812
Author(s):  
Tuangphorn Prasitthikun ◽  
X. Wu ◽  
Tsugio Sato ◽  
Charusporn Mongkolkachit ◽  
Pornapa Sujaridworakun

High efficiency BiOBr/GO composites photocatalyst were successfully synthesized via a facile precipitation method. The precursors were prepared by dissolving Bi (NO3)3.5H2O and KBr in glycerol and distilled water, respectively. Various amounts (0.1-2 wt%) of graphene oxide were added into the mixed solution precursors, and stirred at room temperature to get precipitated powder without further heat treatment. The obtained products were characterized for phase, morphology, optical properties and surface area by X-ray diffraction (XRD), transmission electron microscopy (TEM), filed-emission scanning electron microscopy (FE-SEM), UV-Vis diffuse reflection spectroscopy (DRS) and Brunauer–Emmett–Teller (BET), respectively. The morphology and structure of as-synthesized samples were composed of numerous fine plates of BiOBr dispersed on the GO sheets. The photocatalytic activities of BiOBr/GO composites were evaluated by rhodamine B degradation under visible light irradiation. As the results, the significant increase in photodegradation of BiOBr/GO composite comparing with pure BiOBr was observed. Among all samples, the composite with 1 wt% of graphene oxide showed the highest photocatalytic performance.


2017 ◽  
Vol 757 ◽  
pp. 88-92
Author(s):  
Cheewita Suwanchawalit ◽  
Kamonchanok Roongraung ◽  
Supat Buddee ◽  
Sumpun Wongnawa ◽  
Avinash Patil

Silver-modified bismuth vanadate (Ag-BiVO4) photocatalysts were easily prepared via the co-precipitation method. The effects of silver contents on the chemical properties of BiVO4 were evaluated. The prepared Ag-BiVO4 samples were characterized by several techniques such as X-ray diffractometry (XRD), scanning electron microscopy (SEM), and diffused reflectance UV-Vis spectroscopy (DRS). The mixed phase of monoclinic scheetlite structure and characteristic peaks of silver particles were found. Silver contents strongly affect the morphology of the prepared Ag-BiVO4 samples. DRS spectra revealed that the synthesized Ag-BiVO4 samples exhibited strong absorption in the visible region. The absorption in the visible zone is responsible for the high photocatalytic activity of Ag-BiVO4 under visible light irradiation. The photocatalytic degradation of methylene blue under visible light irradiation was studied using the BiVO4 as photocatalysts. The photocatalytic results reveal that the prepared Ag-BiVO4 samples could degrade the methylene blue dye.


2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Liqin Qin ◽  
Pingfang Tao ◽  
Xiaosong Zhou ◽  
Qi Pang ◽  
Chunjie Liang ◽  
...  

A facile method for the synthesis of Ag3PO4visible light photocatalyst has been developed to improve the photocatalytic activity and stability. The as-prepared samples are investigated by X-ray powder diffraction, scanning electron microscopy, infrared spectroscopy, photoluminescence (PL) spectroscopy, and UV-Vis diffuse reflectance spectroscopy techniques. The results reveal that the prepared Ag3PO4has cube structure with a band gap of 2.26 eV. The as-prepared samples show higher photocatalytic activity for methylene blue (MB) degradation than that of N-TiO2under visible light irradiation.


2013 ◽  
Vol 668 ◽  
pp. 338-342 ◽  
Author(s):  
Le Wei Qin ◽  
Ke Feng He ◽  
Wan Ping Chen

Nanostructured AgBr/TiO2 visible light photocatalyst was prepared through deposition-precipitation method with AgNO3, KBr and Ti(OBu )4 as the precursors. Though the photocatalyst showed a relatively high photocatalytic efficiency for degradation of methyl orange in water under visible light irradiation in the first cycle, its efficiency was obviously decreased in the subsequent cycles. X-ray diffraction indicated that there existed a dramatic crystalline growth of AgBr in the AgBr /TiO2 nanocomposite after visible light irradiation, which must increase the recombination rate of photo-generated electrons and holes and be responsible for the observed decrease in photocatalytic efficiency. Photo-induced crystalline growth of AgBr may be a limiting factor for the lifetime of AgBr/TiO2 visible light photocatalyst and more attention should be paid to it.


2021 ◽  
Author(s):  
Senthilkumar M ◽  
C. Arunagiri

Abstract FexZn1-xO (x = 0, 0.05, 0.075, 0.1 M) nanoparticles based photocatalysts were synthesized by a chemical precipitation method and characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray emission (EDX) and UV–Vis spectroscopy. The photocatalytic efficiency of FexZn1-xO catalysts was assessed under visible light irradiation using the degradation of methylene blue (MB) and methyl orange (MO) dye in aqueous solution. The present investigation shows that the effect of optimized parameters (pH, catalyst dosage and initial dye concentration) and doping concentrations plays significant role in photocatalytic activity. The detailed photocatalytic mechanism for the enhancement of photocatalytic activity has also been proposed.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 305
Author(s):  
Alia Raees ◽  
Muhammad Asghar Jamal ◽  
Ikram Ahmed ◽  
Mika Silanpaa ◽  
Tahani Saad Algarni

Removal of hazardous organic dyes from polluted water bodies requires the introduction of strong adsorbents and photocatalysts to industrial wastewaters. Herein, photocatalytic CeO2 nanoparticles and CeO2/CuO nanocomposite were synthesized following a co-precipitation method for low cost elution of methylene blue (MB) from water. The crystallinity and surface structure of the as-prepared materials have been analyzed using characterization techniques including X-ray powder diffraction (XRPD), field emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), ultra-violet visible spectroscopy (UV–Vis), and Fourier-transform infrared spectroscopy (FTIR). The average particle size of both the nano scaled samples were approximately 20–30 nm. The photocatalytic properties of CeO2/CuO were investigated under visible light against methylene blue (MB). The results showed 91% photodegradation of MB organic pollutant in 3 h as monitored by UV–Vis spectroscopy. Absorbance peaks appeared at around 670 nm corresponding to degradation of MB. Such output displayed the effectiveness of Ce nanocomposites for environmental benefits. Hence, CeO2/CuO nanocomposite could be useful for treatment of industrial wastewaters by removing hazardous MB dye.


Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 788
Author(s):  
Beibei Zhang ◽  
Lu Zhang ◽  
Yulong Zhang ◽  
Chao Liu ◽  
Jiexiang Xia ◽  
...  

In this work, a simple chemical precipitation method was employed to prepare spherical-like Ag3PO4 material (IL-Ag3PO4) with exposed {111} facet in the presence of reactive ionic liquid 1-butyl-3-methylimidazole dihydrogen phosphate ([Omim]H2PO4). The crystal structure, microstructure, optical properties, and visible-light photocatalytic performance of as-prepared materials were studied in detail. The addition of ionic liquids played a crucial role in forming spherical-like morphology of IL-Ag3PO4 sample. Compared with traditional Ag3PO4 material, the intensity ratio of {222}/{200} facets in XRD pattern of IL-Ag3PO4 was significantly enhanced, indicating the main {111} facets exposed on the surface of IL-Ag3PO4 sample. The presence of exposed {111} facet was advantageous for facilitating the charge carrier transfer and separation. The light-harvesting capacity of IL-Ag3PO4 was larger than that of Ag3PO4. The photocatalytic activity of samples was evaluated by degrading rhodamine B (RhB) and p-chlorophenol (4-CP) under visible light. The photodegradation efficiencies of IL-Ag3PO4 were 1.94 and 2.45 times higher than that of Ag3PO4 for RhB and 4-CP removal, respectively, attributing to a synergy from the exposed {111} facet and enhanced photoabsorption. Based on active species capturing experiments, holes (h+), and superoxide radical (•O2−) were the main active species for visible-light-driven RhB photodegradation. This study will provide a promising prospect for designing and synthesizing ionic liquid-assisted photocatalysts with a high efficiency.


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