scholarly journals Photocatalytic activity of Pr-modified TiO2 for the degradation of bisphenol A

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Denise S. Cordeiro ◽  
Fernando L. Cassio ◽  
Larissa Ciccotti ◽  
Thiago L. R. Hewer ◽  
Paola Corio ◽  
...  

AbstractPraseodymium doped TiO2 nanoparticles were successfully prepared by the sol–gel method and characterized by X-ray powder diffraction, N2 adsorption–desorption isotherm, and UV–vis spectroscopy. The effects of the dopant on the crystallite size, specific surface area, average pore diameter, pore volume, and bandgap energy were investigated. The photocatalytic activity of the catalysts was evaluated by bisphenol A degradation and mineralization, which is a representative endocrine disruptor. Furthermore, under visible light irradiation the Pr-modified TiO2 photocatalysts exhibited higher photocatalytic efficiency than unmodified TiO2. When praseodymium was loaded (1.0–5.0%) onto the surface of TiO2, the rates of degradation and mineralization were increased 3–5 times.

2013 ◽  
Vol 631-632 ◽  
pp. 116-120
Author(s):  
Peng Zheng ◽  
Lin Hua Zhu ◽  
Tian Si ◽  
Yan Lin Sun

Using polyethylene oxide (PEO) as template, the new types of mesoporous phosphate compound which belongs to NaZr2(PO4)3(NZP) family were synthesized by copreciptate, sol-gel and mechanochemical activation(MA) route respectively. The physical phase and pore structure of the synthesized powder materials were characterized by X-ray diffraction (XRD) and N2 adsorption–desorption. The results showed that the crystalline NZP family compound with mesoporous structure is formed by sol-gel route followed with calcination as well as MA method followed with hydrothermal treatment when the mole ratio of PEO to Zr is 1:10, and the specific surface area, average pore diameter and pore volume of the synthesized powder is 20-50m2/g, 3-6.nm and 0.05-0.12cm3/g respectively. The above research results indicate that it is promising to expand the application field of the powder of NZP family from low thermal expansion ceramics to catalytic materials.


2021 ◽  
Vol 11 (5) ◽  
pp. 706-716
Author(s):  
Nada D. Al-Khthami ◽  
Tariq Altalhi ◽  
Mohammed Alsawat ◽  
Mohamed S. Amin ◽  
Yousef G. Alghamdi ◽  
...  

Different organic pollutants have been remediated photo catalytically by applying perovskite photocatalysts. Atrazine (ATR) is a pesticide commonly detected as a pollutant in drinking, surface and ground water. Herein, FeYO3@rGO heterojunction was synthesized and applied for photooxidation decomposition of ATR. First, FeYO 3nanoparticles (NPs) were prepared via routine sol-gel. After that, FeYO3 NPs were successfully incorporated with different percentages (5, 10, 15 and 20 wt.%) of reduced graphene oxide (rGO) in the synthesis of novel FeYO3@rGO photocatalyst. Morphological, structural, surface, optoelectrical and optical characteristics of constructed materials were identified via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), adsorption/desorption isotherms, diffusive reflectance (DR) spectra, and photoluminescence response (PL). Furthermore, photocatalytic achievement of the constructed materials was evaluated via photooxidative degradation of ATR. Various investigations affirmed the usefulness of rGO incorporation on the advancement of formed photocatalysts. Actually, novel nanocomposite containing rGO (15 wt.%) possessed diminished bandgap energy, as well as magnified visible light absorption. Furthermore, such nanocomposite presented exceptional photocatalytic achievement when exposed to visible light as ATR was perfectly photooxidized over finite amount (1.6 g · L-1) from the optimized photocatalyst when illuminated for 30 min. The advanced photocatalytic performance of constructed heterojunctions could be accredited mainly to depressed recombination amid induced charges. The constructed FeYO3@rGO nanocomposite is labelled as efficient photocatalyst for remediation of herbicides from aquatic environments.


2012 ◽  
Vol 455-456 ◽  
pp. 110-114 ◽  
Author(s):  
Xuan Dong Li ◽  
Xi Jiang Han ◽  
Wen Ying Wang ◽  
Xiao Hong Liu ◽  
Yan Wang ◽  
...  

Nb-doped TiO2 powders with different concentrations of Nb have been synthesized by a sol-gel method and characterized by a series of technologies including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy. The photocatalytic activity of Nb-doped TiO2 is evaluated by degradation efficiency of methyl orange in aqueous solution. The results indicate that the photocatalytic activity of Nb-doped TiO2 synthesized with a Nb/Ti molar ratio of 5% is higher than that of TiO2 under the visible light.


2013 ◽  
Vol 743-744 ◽  
pp. 434-437
Author(s):  
Miao Lv ◽  
Guo Tong Qin ◽  
Wei Wei

TiO2aerogel fibers have been fabricated by electron span combined supercritical drying technique. Polyvinylpyrrolidone (PVP)/TiO2composite fibers are prepared by electrospinning PVP and TiO2precursor Ti (OC4H9)4. TiO2aerogel fibers are obtained by supercritical drying PVP/TiO2composite fibers using ethanol as media. Structural of the aerogel fibers was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and N2adsorption at 77 K. The effect of mass ratio of PVP/TiO2was investigated. SEM shows that pore structure of nanofibers was well developed, with the diameter of nanofibers about 2 μm. N2adsorption/desorption data show that the highest surface area of aerogel fibers reached 241.6 m2/g with the average pore diameter about 10 nm. The aerogel fibers were anatase type TiO2.


2017 ◽  
Vol 14 (1) ◽  
pp. 17-25
Author(s):  
Wenjie Zhang ◽  
Jiao Yang ◽  
Ling Du

Background: Pyrochloro structured Sm2Ti2O7 has photocatalytic activity on degradation of organic substances and on hydrogen evolution from water. Powder materials usually encounter the obstacle of separating from treated water. HZSM-5 zeolite is a kind of porous structured material with large surface area. Its role as a support for Sm2Ti2O7 is interesting. Methods: The supported Sm2Ti2O7 was synthesized using sol-gel method. The composite χSm2Ti2O7/HZSM-5 was characterized by XRD, SEM, TEM, FT-IR/FIR, UV-Vis DRS, N2 adsorption- desorption and XPS measurements. Photocatalytic degradation of Reactive Brilliant Red X-3B (RBR X-3B) was measured to evaluate the activity of the composite. Results: Sm2Ti2O7 is in the pyrochlore phase after loading on the surface of HZSM-5 zeolite. The crystal cell of pyrochlore Sm2Ti2O7 continuously expanses with decreasing Sm2Ti2O7 loading content in the composite. Bandgap energy of Sm2Ti2O7 is enlarged after supporting. The specific surface area of Sm2Ti2O7 was enlarged from 9.8 m2/g to 93 m2/g after loading. Both of the adsorption capacity and photocatalytic activity of the χSm2Ti2O7/HZSM-5 are greater than those of pure Sm2Ti2O7. After 120 min of irradiation, 73.1% of the initial RBR X-3B molecules are decomposed on 70%Sm2Ti2O7/HZSM-5, and only 27.7% of the dye is decomposed on the bare Sm2Ti2O7. Conclusion: Sm2Ti2O7 crystal growth is constrained after loading due to dispersion of Sm2Ti2O7 on the surface of HZSM-5. The specific surface area of Sm2Ti2O7 is significantly enlarged after loading. All the supported samples have greatly enhanced photocatalytic activity as compared to the bare Sm2Ti2O7.


2011 ◽  
Vol 391-392 ◽  
pp. 728-731 ◽  
Author(s):  
Wen Churng Lin ◽  
Wein Duo Yang

Different concentration of copper (II) doped TiO2 photocatalyst powders were synthesized through the sol-gel method and characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET)-specific surface area, transmission electron microscopy (TEM), and Ultraviolet–Visible (UV-Vis) spectroscopy. Cu2+-doping in the TiO2 promotes the particle growth, decreases the specific surface areas of powders, extends the absorption to visible light regions, and exhibits the vis-photocatalytic activity for methylene blue (MB) degradation. Appropriate content of Cu2+-doping is an effective means to improve the photocatalytic activity of TiO2 for MB degradation under visible light irradiation.


2015 ◽  
Vol 1087 ◽  
pp. 218-222
Author(s):  
Siti Aida Ibrahim ◽  
Srimala Sreekantan

Nanostructured Fe-TiO2 and TiO2 with anatase structure were synthesized via combination method of sol-gel and peptization process. The samples were characterized by X-ray diffraction (XRD), Transmission emission microscopy (TEM) and UV-Vis spectroscopy (UV-Vis). The presence of Fe3+ ion shifted the absorption profile of TiO2 to the longer wavelength side of the spectrum, indicating an obvious photocatalytic activity under visible irradiation. Photocatalytic activity of the samples were evaluated by methyl orange (MO) discolouration under UV-light irradiation. Compared with the pure TiO2 nanoparticles, the Fe-TiO2 nanoparticles exhibited higher photocatalytic activity with 95% discoloration within 2 h.


2007 ◽  
Vol 1 (1-2) ◽  
pp. 5-9 ◽  
Author(s):  
Zoltán Ecsedi ◽  
Ioan Lazău ◽  
Cornelia Păcurariu

The effects of polyvinyl alcohol (PVA) template and calcinations temperatures on the characteristics of the alumina films were investigated. The samples were prepared by sol-gel method using aluminium triisopropylate precursor. The variation of microstructure, pore size and pore volume, were determined by nitrogen adsorption/ desorption analysis and the macropore size distribution was determined using mercury porosimetry. TEM and SEM were used to observe the texture of these samples and the particle morphology. Experimental observation after drying and annealing shows that it is possible to produce crack free nanoporous alumina films using polyvinyl alcohol template. The obtained alumina samples have macroporous microstructure (with the average pore diameter dav = 34.9 ?m, for sample prepared with 42.5 wt% of PVA addition and annealed at 1000?C) with high portion of mesopores (with the average pore diameter Dav = 14.0 nm for the same sample).


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.


2021 ◽  
Vol 16 (4) ◽  
pp. 804-815
Author(s):  
Candra Purnawan ◽  
Sayekti Wahyuningsih ◽  
Oktaviani Nur Aniza ◽  
Octaria Priwidya Sari

TiO2 and TiO2 doped Cd, Co, Mn (TiO2-M) were synthesized with a sol-gel method, and the photocatalytic activity of Remazol Brilliant Blue R and Remazol Yellow FG has been conducted. TiO2-M (Cd, Co, Mn) was synthesized with the mol Ti:M ratio of 3:1, and the materials were calcined at 300, 400, and 500 °C. The materials were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX), and UV-Vis Reflectance. The XRD result shows that at the temperature of 300 °C TiO2 and TiO2-M formed tend to be amorphous. At 400 °C the anatase phase is formed, while at 500 °C the rutile phase begins to form. And overall, the crystallinity of TiO2 is higher than metal-doped TiO2. The UV-Vis Reflectance result showed that the bandgap energy of all doping materials (TiO2-M) decreased. The larger the metal ion radius of dopant, the larger the crystal size obtained  and then the higher the bandgap obtained. The results of SEM-EDX showed that the morphology of TiO2 was spherical and regular, whereas the morphology of TiO2-M had a smoother surface due to the influence of metal doping. Photocatalytic activity of TiO2-M on Remazol Brilliant Blue R and Remazol Yellow FG was greater than TiO2. The optimum pH of the solution was obtained at pH 5 and the optimum catalyst phase was obtained at the anatase phase. The percentages degradation for 30 min of Remazol Brilliant Blue R were 67.34% (TiO2), 92.12% (TiO2-Co), 85.47% (TiO2-Mn), and 83.91% (TiO2-Cd), while for Remazol Yellow FG they were 58.84% (TiO2), 74.61% (TiO2-Co), 67.93% (TiO2-Mn) and 64.19% (TiO2-Cd), respectively. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 


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