Effect of Niobium on the Structure and Photoactivity of Anatase (TiO2) Nanoparticles

2006 ◽  
Vol 6 (3) ◽  
pp. 762-770 ◽  
Author(s):  
Masanori Hirano ◽  
Kazumasa Matsushima

Anatase-type TiO2 nanoparticles doped with 0–30 mol% niobium were directly formed from precursor solutions of TiOSO4 and NbCl5 under mild hydrothermal conditions at 120–180 °C for 5 h using the hydrolysis of urea. When the niobium content increased from 0 to 30 mol%, the crystallite size of anatase increased from 8.5 to 19 nm. The band gap of anatase was slightly decreased by making solid solutions with niobium. Their photocatalytic activity and adsorptivity were evaluated separately by the measurement of the concentration of methylene blue (MB) remained in the solution after maintained in the dark or under UV-light irradiation. To form anatase-type solid solutions by doping 5–15 mol% niobium into TiO2 was effective for improvement of the photoactivity of TiO2. The photocatalytic activity (the photooxidation rate) and the adsorption amount of MB for the sample containing 15 mol% niobium became more than approximately nine times and six times as much as those of the hydrothermal anatase-type pure TiO2, respectively.

2012 ◽  
Vol 512-515 ◽  
pp. 1677-1681
Author(s):  
Feng Zhou ◽  
Ying Qing Fu ◽  
Xin Wan

A facile route was demonstrated to obtain an efficient graphene-hybridized TiO2 photocatalyst. The photodegradation results of Methylene Blue over graphene hybridized with TiO2 showed that the photocatalytic activity could be significantly enhanced under UV light irradiation. The structure between TiO2 and graphene as well as its effect on the photocatalytic activity were systematically investigated. The mechanism of the enhanced photocatalytic activity is based to the high migration efficiency and the inhibition of recombination of photoinduced electron-hole pairs. The graphene hydridization is proven to be a promising approach to develop highly efficient and stable photocatalysts under UV light irradiation.


RSC Advances ◽  
2014 ◽  
Vol 4 (58) ◽  
pp. 30798-30806 ◽  
Author(s):  
Jian Cao ◽  
Qianyu Liu ◽  
Donglai Han ◽  
Shuo Yang ◽  
Jinghai Yang ◽  
...  

ZnS–graphene nanocomposites exhibit excellent photocatalytic activity for degradation of methylene blue under UV light irradiation.


2012 ◽  
Vol 488-489 ◽  
pp. 1519-1524 ◽  
Author(s):  
Kittirong Srimuangmak ◽  
Sutham Niyomwas

In this study titanium dioxide nanotube (TNT) were prepared by anodization method. The effects of the temperature, time and voltage on the anodization process were investigated in detail. Photocatalytic activity of the TNT films was evaluated in terms of the degradation of methylene blue in aqueous solution under UV light irradiation. The results showed that the optimization of temperature, voltage and time on anodization process were 45oC, 20 V and 1 day, respectively. Consequently, these results indicate that the optimization of anodization process is critical to achieve the high performance of photocatalytic reaction.


2013 ◽  
Vol 631-632 ◽  
pp. 504-510
Author(s):  
Su Qin Liu ◽  
Ying Liang

Anatase titania (TiO2) films with highly photocatalytic activity were prepared by hydrothermal treatment of amorphous TiO2 nanotubes (NTs) via electrochemical anodization of titanium (Ti) in fluorine-containing electrolyte. The as-prepared TiO2 films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). The photocatalytic activity of the as-prepared TiO2 films was evaluated by the photocatalytic degradation of methyl orange (MO) aqueous under UV-light irradiation. The effects of hydrothermal temperature and time on the morphologies, microstructure and photocatalytic activity of TiO2 films were investigated and discussed. It was found that TiO2 NTs were converted to nanoparticles after hydrothermal treatment. The mechanism of deformation of TiO2 NTs was discussed. Hydrothermal treatment enhances the phase transformation of TiO2 films from amorphous to anatase and crystallization of anatase. An optimal hydrothermal condition (150 oC for 8 h) was determined. The anatase TiO2 films prepared under optimal hydrothermal conditions posses larger surface area and higher relative anatase crystallinity and its photocatalytic activity is higher than that of anatase TiO2 films prepared under other hydrothermal conditions.


Author(s):  
Muhamad Rafiq Kamaluddin ◽  
Nur Izzah Iwanina Zamri ◽  
Eny Kusrini ◽  
Wuwuh Wijang Prihandini ◽  
Abdul Hanif Mahadi ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1326 ◽  
Author(s):  
Roberta Grazia Toro ◽  
Mohamed Diab ◽  
Tilde de Caro ◽  
Mona Al-Shemy ◽  
Abeer Adel ◽  
...  

Different amounts of a stable aqueous TiO2 hydrosol were used to fabricate paper sheets having photocatalytic activity. The TiO2 hydrosol was prepared in aqueous medium using titanium butoxide as precursor and acetic acid as catalyst for the hydrolysis of titanium butoxide. An aging process at room temperature and atmospheric pressure was finally applied to obtain crystalline anatase TiO2 hydrosol. The effects of different TiO2 hydrosol loadings on the mechanical strength and barrier properties of modified paper sheets were investigated in detail. The photocatalytic behavior of TiO2-modified paper sheets was investigated as well using methylene blue (MB) as target pollutant.


2016 ◽  
Vol 74 (10) ◽  
pp. 2325-2336 ◽  
Author(s):  
W. M. A. El Rouby ◽  
A. A. Farghali ◽  
A. Hamdedein

Cerium (IV) oxide (CeO2), samarium (Sm) and gadolinium (Gd) doped CeO2 nanoparticles were prepared using microwave technique. The effect of microwave irradiation time, microwave power and pH of the starting solution on the structure and crystallite size were investigated. The prepared nanoparticles were characterized using X-ray diffraction, FT-Raman spectroscopy, and transmission electron microscope. The photocatalytic activity of the as-prepared CeO2, Sm and Gd doped CeO2 toward degradation of methylene blue (MB) dye was investigated under UV light irradiation. The effect of pH, the amount of catalyst and the dye concentration on the degradation extent were studied. The photocatalytic activity of CeO2 was kinetically enhanced by trivalent cation (Gd and Sm) doping. The results revealed that Gd doped CeO2 nanoparticles exhibit the best catalytic degradation activity on MB under UV irradiation. For clarifying the environmental safety of the by products produced from the degradation process, the pathways of MB degradation were followed using liquid chromatography/mass spectroscopy (LC/MS). The total organic carbon content measurements confirmed the results obtained by LC/MS. Compared to the same nanoparticles prepared by another method, it was found that Gd doped CeO2 prepared by hydrothermal process was able to mineralize MB dye completely under UV light irradiation.


2021 ◽  
Vol 78 (5) ◽  
pp. 2849-2865
Author(s):  
Bircan Haspulat Taymaz ◽  
Recep Taş ◽  
Handan Kamış ◽  
Muzaffer Can

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