scholarly journals Preparation and characterization of Fe-doped TiO2 powders for solar light response and photocatalytic applications

2012 ◽  
Vol 6 (1) ◽  
pp. 21-36 ◽  
Author(s):  
Ibram Ganesh ◽  
Polkampally Kumar ◽  
Abhishek Gupta ◽  
Panakati Sekhar ◽  
Kalathur Radha ◽  
...  

Different amounts of Fe-doped TiO2 (with 0.1 to 10 wt.% Fe) powders were prepared at temperatures in the range of 400 and 800?C following a conventional co-precipitation technique and were thoroughly characterized by means of X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), Fourier-transform Raman (FT-Raman), diffuse reflectance spectroscopy (DRS), BET surface area, zeta potential and flat band potential measurements. Photocatalytic ability of Fe-doped TiO2 powders was evaluated by means of methylene blue (MB) degradation experiments conducted under the irradiation of simulated solar light. Characterization results suggested that as a dopant Fe stabilized TiO2 in the form of anatase phase, reduced its band gap energy and adjusted its flat band potentials in such a way that these powders can be employed for photoelectrolysis of water into hydrogen and oxygen in photoelectrochemical (PEC) cells. The 0.1 wt.% Fe-doped TiO2 exhibited highest activity in the photocatalytic degradation of MB. The kinetic studies revealed that the MB degradation reaction follows the Langmuir-Hinshelwood first order reaction rate.

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Ibram Ganesh ◽  
A. K. Gupta ◽  
P. P. Kumar ◽  
P. S. C. Sekhar ◽  
K. Radha ◽  
...  

Different amounts of Ni-doped TiO2( to 10%) powders and thin films were prepared by following a conventional coprecipitation and sol-gel dip coating techniques, respectively, at 400 to 800°C, and were thoroughly characterized by means of XRD, FT-IR, FT-Raman, DRS, UV-visible, BET surface area, zeta potential, flat band potential, and photocurrent measurement techniques. Photocatalytic abilities of Ni-doped TiO2powders were evaluated by means of methylene blue (MB) degradation reaction under simulated solar light. Characterization results suggest that as a dopant, Ni stabilizes TiO2in the form of anatase phase, reduces its bandgap energy, and adjusts its flat band potentials such that this material can be employed for photoelectrochemical (PEC) oxidation of water reaction. The photocatalytic activity and photocurrent ability of TiO2have been enhanced by doping of Ni in TiO2. The kinetic studies revealed that the MB degradation reaction follows the Langmuir-Hinshelwood first-order reaction relationship.


Author(s):  
Irwing M. Ramírez-Sánchez ◽  
Erick R. Bandala

Iron Doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low fluence values of UV-radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-Ray Photoelectron Spectroscopy (XPS) technique. The XPS evidenced that ferric ion (Fe3+) was in the lattice of TiO2 and co-dopants no intentionally added were also present due to the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radical (•OH) and estriol (E3) degradation. Fe-TiO2 materials accomplished E3 degradation, and it was found that the catalyst with 0.3 at. % content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV-irradiation compared with no intentionally Fe-added TiO2 (zero-iron TiO2) and Aeroxide® TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV-irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.


2010 ◽  
Vol 113-116 ◽  
pp. 1945-1950 ◽  
Author(s):  
Jie Luo ◽  
Xin Yuan Yang ◽  
De Liang Li

Using cesium nitrate and strontium nitrate as doping metal ions source, Cs-doped TiO2 and Sr-doped TiO2 photocatalysts were successfully synthesized through the hydrolysis of tetrabutyl titanate by an acid-catalyzed sol-gel method. The photocatalytic activities of these catalysts prepared at 600 °C for 2 h were evaluated by the degradation of methyl orange in aqueous solution under solar light irradiation, and the as-prepared samples with higher photocatalytic efficiency were characterized by means of X-ray diffraction (XRD) and UV-Vis absorption spectroscopy. The XRD patterns indicate that the crystal structure still remains as anatase phase for the doped samples, and the average crystal size of TiO2, 0.1 at% Cs-doped TiO2 and 0.3 at% Sr-doped TiO2 is 21.3, 13.1 and 10.8 nm, respectively. The band gap absorption shows red shift to the visible region for the doped samples from the UV-Vis spectrogram. The results show that the photocatalytic activity of TiO2 nanoparticles doped with Cs+ and Sr2+ exhibits a significant improvement and their degradation efficiencies are more than 30% in comparison with those of TiO2 under the same condition, and the optimal doping concentration is determined to be 0.1 at% and 0.3 at% for Cs+ and Sr2+, respectively.


2020 ◽  
Vol 20 (9) ◽  
pp. 5418-5425
Author(s):  
Dien-Trung Nguyen ◽  
Cam-Anh Ha ◽  
Tri Nguyen

In this work, titanium oxide catalysts were synthesized by the hydrothermal method from titanium isopropoxide (TTIP) as a precursor under acidic (Ti-A1 and Ti-A2), neutral (Ti-W) and alkaline (Ti-B) media. Characteristics of the catalysts were identified by various methods including X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller adsorption, UV-Vis diffuse reflectance spectroscopy, transmission electron microscopy, and Raman spectroscopy. The phase composition and PZC value of the obtained catalysts depended on the hydrothermal medium and the amount of TTIP: pure anatase and brookite phase formed at neutral and alkaline medium, respectively; whereas acidic medium favored the formation of anatase/rutile mixed phase and anatase phase decreased with the increasing amount of TTIP. The band gap energy of the synthesized catalysts was approximately 3.08–3.23 eV. Photocatalytic activity of synthesized catalysts was surveyed in the degradation of cinnamic acid (CA) solution at various pH in the region from 3.8 to 9.0 under UV irradiation. Photocatalytic oxidation was favorable in an acidic environment. At acidic pH values (3.8 and 5.0), the CA conversion was in the order of Ti-A2 ≥ Ti-A1 > Ti-P25 > Ti-W ≫ Ti-B, whereas it followed Ti-P25 > Ti-A1 > Ti-A2 ≈ Ti-W > Ti-B at pH 7.0 as well as pH 9.0.


2020 ◽  
Vol 9 (4) ◽  
pp. 42-48
Author(s):  
Nui Pham Xuan ◽  
Hoa Nguyen Thi ◽  
Tien Nguyen Trung ◽  
Tai Le Huu ◽  
Thi Tran Thi Van

In this research, photocatalytic materials of TiO2, Ag-TiO2, Ag-TiO2/perlite were synthesized by the sol-gel method. By combining the photocatalytic activity between Ag-TiO2 and Perlite mineral, the Ag-TiO2/perlite composite has overcome the disadvantages of pristine TiO2, such as high band gap energy, low light utilization and easy recombination of electrons and holes. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption isotherm, UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The photocatalytic activity of the samples was tested for degradation of methylene blue (MB) under solar light irradiation. Photodegradation studies revealed a 95% removal of MB dye via the synthesized Ag-TiO2/perlite after 150 min of irradiation. Reusability of this hybrid photocatalyst system was tested and only a 3% decrease was observed after four cycles.


2015 ◽  
Vol 72 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Mehrzad Feilizadeh ◽  
Amin Delparish ◽  
S. Toufigh Bararpour ◽  
Hamed Abedini Najafabadi ◽  
S. Mohammad Esmaeil Zakeri ◽  
...  

To overcome the drawback of poor solar light utilization brought about by the narrow photoresponse range of TiO2, a silver and sulfur co-doped TiO2 was synthesized. Using the prepared catalyst, solar photocatalytic degradation of 2-nitrophenol (2-NP) by a TiO2-based catalyst was studied for the first time. Effects of the co-doping on the structural, optical and morphological properties of the synthesized nanoparticles were investigated by different characterization methods: X-ray diffraction, N2 adsorption–desorption measurements, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, UV–visible diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy. Solar experiments showed that the co-doping with silver and sulfur significantly increased the photocatalytic activity. In various initial concentrations of 2-NP more than 99% of the contaminant was decomposed by Ag-S/TiO2 in less than 150 minutes, while the degradation efficiency was much less in the presence of bare TiO2. Kinetic studies suggested that solar photocatalytic degradation of 2-NP is consistent with the Langmuir–Hinshelwood model. The rate constant of the reaction and adsorption constant of the modified photocatalyst were found to be 2.4 and 4.1 times larger than that of bare TiO2, respectively.


2016 ◽  
Vol 13 (1) ◽  
pp. 99
Author(s):  
Siti Zulaikha Suhaili ◽  
Muhamad Kamil Yaakob ◽  
Siti Irma Yuana Saaid ◽  
Umi Sarah Jais

Pure TiO2 and Cr doped TiO2 (0.1-1.0wt% Cr) nanoparticles were synthesized via sol gel method. This study focuses on narrowing the TiO2 band gap energies in order to enhance the photocatalytic efficiency under visible light. The synthesized samples were characterized by X-Ray diffraction method (XRD), field emmision (FESEM) and also UV-Vis diffuse reflectance spectroscopy (DRS).The photocatalytic activity under sunlight irradiation was demonstrated by photocatalytic decomposition of methylene blue in water using UV/Vis spectrophotometer. The XRD analysis of pure TiO2 and doped TiO2 calcined at 500oC showed a mixture of anatase and rutile phases with decreasing crystallites size from 13.3nm to 11.6nm as the concentration of Cr was increased. The anatase-rutile phase transformation increased from 28.8% to 57.4%. An indication shows that at 0.75wt%, Cr the anatase and rutile phases have equal composition percentage. This study demonstrated that band gap energy of TiO2 was reduced with Cr doping which could enhance the photocatalytic efficiency. Sample containing 1.0wt% exhibit the lowest optical band gap energy at 2.86 eV. The optimum chromium doping concentration was found to be at 0.1 wt% Cr corresponding to band gap energy of 2.87 eV and degradation rate of 84%. 


2016 ◽  
Vol 13 (1) ◽  
pp. 99
Author(s):  
Siti Zulaikha Suhaili ◽  
Muhamad Kamil Yaakob ◽  
Siti Irma Yuana Sheikh Mohd Saaid ◽  
Umi Sarah Jais

Pure TiO2 and Cr doped TiO2 (0.1-1.0wt% Cr) nanoparticles were synthesized via sol gel method. This study focuses on narrowing the TiO2 band gap energies in order to enhance the photocatalytic efficiency under visible light. The synthesized samples were characterized by X-Ray diffraction method (XRD), field emmision (FESEM) and also UV-Vis diffuse reflectance spectroscopy (DRS).The photocatalytic activity under sunlight irradiation was demonstrated by photocatalytic decomposition of methylene blue in water using UV/Vis spectrophotometer. The XRD analysis of pure TiO2 and doped TiO2 calcined at 500oC showed a mixture of anatase and rutile phases with decreasing crystallites size from 13.3nm to 11.6nm as the concentration of Cr was increased. The anatase-rutile phase transformation increased from 28.8% to 57.4%. An indication shows that at 0.75wt%, Cr the anatase and rutile phases have equal composition percentage. This study demonstrated that band gap energy of TiO2 was reduced with Cr doping which could enhance the photocatalytic efficiency. Sample containing 1.0wt% exhibit the lowest optical band gap energy at 2.86 eV. The optimum chromium doping concentration was found to be at 0.1 wt% Cr corresponding to band gap energy of 2.87 eV and degradation rate of 84%.


Author(s):  
G. Nagaraj ◽  
R.A. Senthil ◽  
Rajender Boddula ◽  
K. Ravichandaran

: Herein, we reported a simple and effective approach to synthesis of pure and Ni2+ doped TiO2 nanorods by a photon-induced method (PIM) followed by calcination at 850 ºC in air atmosphere. Basically, the PIM was used to tuning the properties of as-prepared TiO2 photocatalyst. These obtained samples were further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM) and UV-visible diffuse reflectance spectroscopy (UV-vis DRS) analysis. XRD results reveals that the both pure TiO2 and Ni doped TiO2 nanorods has anatase phase up to 850 ºC. The HR-TEM analysis indicates that doping Ni is favourable to the formation of rod-like TiO2 sample. Also, the observed photocatalytic results demonstrates that the Ni doped TiO2 can be achieved a complete degradation of methylene blue (MB) within 30 min under direct sunlight irradiation as compared to pure TiO2. Therefore, this work revealing the doped Ni has a good potential to modification of TiO2 with an excellent photocatalytic activity for water treatment applications.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3874 ◽  
Author(s):  
Abderrahim El Mragui ◽  
Yuliya Logvina ◽  
Luís Pinto da Silva ◽  
Omar Zegaoui ◽  
Joaquim C.G. Esteves da Silva

Pure TiO2 and Fe- and Co-doped TiO2 nanoparticles (NPs) as photocatalysts were synthesized using wet chemical methods (sol-gel + precipitation). Their crystalline structure and optical properties were analyzed using X-ray diffraction (XRD), Raman spectroscopy and Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible light (UV-Vis) diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of the synthesized nanoparticles was evaluated through degradation of carbamazepine (CBZ) under UV-A and visible-light irradiations. The XRD and Raman analyses revealed that all synthesized nanomaterials showed only the anatase phase. The DRS results showed that the absorption edge was blue-shifted for Fe-doped TiO2 NPs. The decrease in charge recombination was evidenced from the PL investigation for both Co-doped and Fe-doped TiO2 nanomaterials. An enhancement in photocatalytic degradation of carbamazepine in aqueous suspension under both UV-A light and visible-light irradiations was observed for Fe-doped Titania NPs by comparison with pure TiO2. These results suggest that the doping cations could suppress the electron/hole recombination. Therefore, the photocatalytic activity of TiO2-based nanomaterials was enhanced.


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