scholarly journals Co/TiO2 nanoparticles: preparation, characterization and its application for photocatalytic degradation of methylene blue

2018 ◽  
Author(s):  
azadeh ebrahimian pirbazari ◽  
Pejman Monazzam ◽  
Behnam Fakhari Kisomi

In this work, TiO2 nanoparticles containing different amounts of cobalt were synthesized by sol-gel method using titanium (IV) isopropoxide and cobalt chloride as titanium and cobalt precursors, respectively. X-ray diffraction (XRD) results showed prepared samples include 100% anatase phase. The presence of cobalt in TiO2 nanoparticle network was established by XRD, scanning electron microscopy equipped with energy dispersive X-ray microanalysis (SEM-EDX), Fourier transform infrared (FT-IR) and N2 physisorption techniques. The increase of cobalt doping enhanced redshif in the diffuse reflectance spectra. The photocatalytic activity of the prepared samples was tested for degradation of methylene blue (MB) as a model of dye. Although the photocatalytic activity of pure TiO2 was found to be higher than that of Co/TiO2 samples under UV irradiation, the presence of 0.24% cobalt dopant in TiO2 nanoparticles resulted in a photocatalyst with the highest activity under visible light

2019 ◽  
Vol 9 (16) ◽  
pp. 3282 ◽  
Author(s):  
Zhongtian Fu ◽  
Song Zhang ◽  
Zhongxue Fu

A series of composite photocatalysts were prepared by using graphene oxide (GO) prepared by modified Hummers method and TiO2 hydrogel prepared by using butyl titanate as raw materials. The composite photocatalyst was characterized through scanning electron microscope(SEM), x ray diffraction (XRD), and Raman spectroscopy, and the degradation effect of pure TiO2 and composite photocatalyst on methylene blue (MB) dye wastewater under different experimental conditions was studied. The results showed that TiO2 in composite photocatalyst was mainly anatase phase and its photocatalytic activity was better than pure TiO2. When the addition of GO reached 15 wt%, the photocatalytic activity was the highest. When 200 mg composite photocatalyst was added to 200 mL synthetic wastewater with a concentration of 10 mg/L and an initial pH of about 8, the degradation rate could reach 95.8% after 2.5 h. It is presumed that the photogenerated charges of GO/TiO2 composite photocatalyst may directly destroy the luminescent groups in the MB molecule and thus decolorize the wastewater, and no other new luminescent groups are generated during the treatment.


2013 ◽  
Vol 345 ◽  
pp. 201-204 ◽  
Author(s):  
Kai Wang ◽  
Lan Bo Di ◽  
Li Juan Zhang ◽  
Gui Fu Dong ◽  
Xiu Ling Zhang

A simple sol-gel method using 1-butyl-3-methylimidazoliun tetrafluoroborate ([C4MIM]BF4) ionic liquid as template agent was used to prepared mesoporous magnetic TiO2/CoFe2O4photocatalysts (denoted as IL-TiO2/CoFe2O4). The photocatalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis. The results showed that well crystallized anatase TiO2in IL-TiO2/CoFe2O4photocatalysts could be obtained when the calcination temperature was as low as 200 °C, and the phase transition temperature from anatase to rutile was increased to 800 °C. BET analysis showed that IL-TiO2/CoFe2O4was mesoporous structure. The photocatalytic activity of the samples was evaluated by photocatalytic degradation of methylene blue (MB). The results showed that photocatalytic activity of IL-TiO2/CoFe2O4was 6 times higher than that of TiO2/CoFe2O4when a low calcination temperature of 350 °C was used.


2015 ◽  
Vol 1123 ◽  
pp. 227-232 ◽  
Author(s):  
Iqriah Kalim Susanto ◽  
Ardiansyah Taufik ◽  
Rosari Saleh

Nanocomposite Fe3O4-CuO-ZnO with different molar ratio of Fe3O4:CuO:ZnO were synthesized using sol-gel method and characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscope, UV-visible diffuse reflectance spectroscopy and vibrating sample magnetometer. The characterization results manifested that the combination of Fe3O4, CuO and ZnO nanoparticles was successful. The photocatalytic activity of nanocomposite with the molar ratio of 1:1:5 was more effective in the degradation of methylene blue under UV light irradiation than pure Fe3O4, CuO, ZnO. The role of photoactive species involved in the photocatalytic reaction was studied and found that holes play the most important role in photodegradation of methylene blue.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Gang Xin ◽  
Yali Meng

Graphitic carbon nitride (g-C3N4) was synthesized at 520°C by the pyrolysis of cyanamide, dicyandiamide, and melamine. The samples were characterized by X–ray diffraction (XRD), UV-visible diffuse reflectance spectra, Fourier transform infrared spectroscopy (FT-IR), and elemental analyzer. The photocatalytic activity of g-C3N4was evaluated by the photodegrading experiments of methylene blue (MB). The results indicated that g-C3N4. A photocatalytic mechanism presumed the MB photodegradation over the C3N4photocatalyst is attributed to photogenerated electron impelled multistep reduction of O2.


2018 ◽  
Vol 2017 (1) ◽  
pp. 184-193 ◽  
Author(s):  
Desireé M. de los Santos ◽  
Sara Chahid ◽  
Rodrigo Alcántara ◽  
Javier Navas ◽  
Teresa Aguilar ◽  
...  

Abstract Photodegradation processes are of great interest in a range of applications, one of which is the photodecomposition of pollutants. For this reason, analysing nanoparticles that improve the efficiency of these processes under solar radiation are very necessary. Thus, in this study, TiO2 was doped with Mo and Cu using low-temperature hydrolysis as the method of synthesis. Pure TiO2 and x%MoS2/Cu/TiO2 nanoparticles were prepared, where x is the theoretical quantity of MoS2 added (0.0%, 1.0%, 5.5%, 10.0%), setting the nominal quantity of Cu at 0.5 wt.%. The samples obtained were characterized by X-ray diffraction, Raman spectroscopy, X-ray electron spectroscopy and UV-Vis spectroscopy in diffuse reflectance mode. The results suggest that the TiO2 structure was doped with the Mo6+ and Cu2+ ions in the position of the Ti4+. The x%MoS2/Cu/TiO2 samples presented lower band gap energy values and greater optical absorption in the visible region than the pure TiO2 sample. Lastly, the photocatalytic activity of the samples was assessed by means of the photodegradation of methylene blue under visible light. The results show that when the quantity of Mo in the co-doped samples increased (x%MoS2/Cu/TiO2) there were significant increases of up to 93% in the photocatalytic activity.


2019 ◽  
Vol 56 ◽  
pp. 28-38 ◽  
Author(s):  
Uraiwan Werapun ◽  
Jaraslak Pechwang

TiO2 and iron-doped TiO2 were synthesized by sol-gel method. TiO2 and 0.5 %mol Fe:TiO2 were calcined at 500 and 800 °C for 3 h. The synthesized particles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-VIS diffuse reflectance spectrophotometry (UV/DRS), scanning electron microscopy (SEM) and scanning electron microscope-energy dispersive X-Ray analysis (SEM-EDX). The XRD patterns of all samples that were calcined at 500 °C showed only anatase phase. On increasing temperature from 500 to 800 °C, the anatase phase transformed to rutile phase. For 0.5 %mol Fe:TiO2, pseudobrookite (Fe2TiO5) phase was observed at 800 °C. The particles that contained rutile showed higher antibacterial activities against E.coli, B. subtilis, and S. aureus than anatase phase, under fluorescent irradiation.


2016 ◽  
Vol 16 (4) ◽  
pp. 4233-4238
Author(s):  
Qinglong Wang ◽  
Kexun Chen ◽  
Yali Zhang

The photocatalytic materials were prepared by sol–gel method: the main raw materials were tetrabutyltitanate and the lanthanum nitrate hexahydrate, bentonite was the carrier to support TiO2.The properties of the composites were characterized by specific surface area (BET), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TG). The photocatalytic degradation of cyanide waste water was used to assess the photocatalytic activity of the materials. The experimental results showed that the suitable content of lanthanum and roasted temperature could improve the photocatalytic activity. When the composites were roasted at 400 °C and the molar ratio of La to Ti was 1%, the photocatalyst reached optimal performance.


2013 ◽  
Vol 853 ◽  
pp. 73-78
Author(s):  
Yan Xi Deng ◽  
Chuan Chuan Liu ◽  
Guang Yang

Diatomite supported Cu-doped TiO2 photocatalysts were synthesized by sol-gel method and characterized by X-ray diffraction (XRD), SEM and UV-vis diffuses reflectance of spectroscopy (DRS). The photocatalytic activity was evaluated by photocatalytic degradation of methylene blue solution under visible light irradiation. The results show that TiO2/diatomite ratio had a great influene on their photocatalytic activities. All prepared Cu-TiO2/diatomite had a better photocatalytic activities in comparison with Cu-TiO2 and the Cu-TiO2(30)/diatomite had higher photocatalytic activity than others. The photocatalytic degradation of methylene blue is due to the breaking of the chormophoric group, rather than the simple decoloration.


2021 ◽  
Vol 19 (9) ◽  
pp. 81-87
Author(s):  
Hind I. Hussein ◽  
Firas H. Abdulrazzak

TiO2 was synthesized in this work by chemical route, when the titanium oxysulfato (TiOSO4) react with 4:6 H2O2/H2O after is dissolved in deionized water. The yellow precipitate was drying at 100oC before heat treated at 400°C to obtain crystalline TiO2. The sample were characterized using FT-IR and X-ray diffraction spectroscopy which identified that product was mixture between two form anatase and rutile. The photocatalytic activity of synthesized TiO2 was tested in the degradation of Eousin yellow which compare with two form of TiO2. Evaluated the results was shown that H2O2 was succeed to preparing TiO2 from TiOSO4 with higher activity then anatase and rutile forms.


2012 ◽  
Vol 599 ◽  
pp. 104-107
Author(s):  
Fang Zhao ◽  
Ya Qiong Zhao ◽  
Yuan Yuan Li ◽  
Gang Ni

This study investigated the effect of cationic, anionic, and nonionic surfactants on the formation, morphology, and surface properties of TiO2 nanoparticles synthesized by modified sol-gel method. The crystalline structures and morphologies of the powder have been characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD results showed TiO2 nanoparticles synthesized with different surfactants only include anatase phase. The TEM analysis revealed the surfactants can enhance dispersion of TiO2 nanoparticles. In contrast, the anionic surfactants showed hightly effects. The photocatalytic activity of samples was tested for degradation of methyl orange (MO) solutions. The results showed photocatalytic activity of the catalyst with surfactants was higher than pure TiO2 under ultraviolet.


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