Synthesis of TiO2-Modified Hydroxyapatite with Various Morphology by Urea-Assisted Hydrothermal Method

2016 ◽  
Vol 868 ◽  
pp. 28-32 ◽  
Author(s):  
Tomoyo Goto ◽  
Tohru Sekino

In this study, we synthesized the TiO2-modified hydroxyapatite (HAp) with various morphologies by hydrothermal treatment using urea decomposition, at 160 oC for 6 h. After hydrothermal treatment, carbonate-substituted HAp and TiO2 (anatase) phases were formed in products using 1.0-0.1 M urea solution. The morphology of synthesized HAp changed from small plate-shaped to long needle-shaped crystals with decreasing the urea concentration. The photocatalytic property for samples was investigated by decoloration test using 25 ppm methylene blue solution. In comparison with HAp samples without TiO2, the TiO2-modified HAp clearly showed the photocatalytic decomposition of methylene blue by UV irradiation.

2011 ◽  
Vol 197-198 ◽  
pp. 786-789 ◽  
Author(s):  
Rui Liu ◽  
Wein Duo Yang ◽  
Hui Ju Chueng

TiO2 nanotubes were synthesized using TiO2 powder as raw material from a hydrothermal method. It was observed that the sample prepared at 130°C and calcined at 450°C only anatase formed, but the sample calcined at 800°C, both anatase and rutile formed. The obtained TiO2 nanotubes prepared at a hydrothermal temperature of 130°C and calcined at 450°C have a greater surface area of 356.8m2/g. Moreover, the TiO2 nanotubes demonstrate the photocatalytic degradation of methylene blue solution effectively by exposing the nanotubes in aqueous solution under visible light.


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.


2013 ◽  
Vol 668 ◽  
pp. 13-16
Author(s):  
Qing Shan Li ◽  
Biao Zhan ◽  
Wei Hong ◽  
Guang Zhong Xing

Opal as a carrier, tetrabutyl titanate as a titanium source, TiO2 loaded on opal was prepared by sol-gel technique. The photocatalysts were characterized by XRD, TEM and UV-VIS absorption spectrum. Their photocatalytic activities were examined by the photocatalytic decolorization of methylene blue solution under UV light irradiation. The effects of calcination temperature, the amount of TiO2 loading and pH on photocatalytic activities were discussed. The results show that TiO2 supported on opal induced enhancement of photocatalytic decolorization rant and TiO2 doping is about 30 wt. % with 92.15% of decolorization rate at 700°C.


1987 ◽  
Vol 8 (3) ◽  
pp. 59-60
Author(s):  
Ichiro TANABE ◽  
Hiroshi FUJIMURA ◽  
Tatsuo OTANI ◽  
Yukinori OKAZAKI ◽  
Tadayoshi TAKEMOTO ◽  
...  

2018 ◽  
Vol 18 (3) ◽  
pp. 403 ◽  
Author(s):  
Eko Sri Kunarti ◽  
Indriana Kartini ◽  
Akhmad Syoufian ◽  
Karolina Martha Widyandari

Synthesis of magnetic photocatalyst, Fe3O4/TiO2-Co, with characterization and photoactivity examination have been conducted. The synthesis was initiated by preparation of Fe3O4 particles using coprecipitation method. The Fe3O4 particles were then coated with TiO2-Co at a various ratio of Fe3O4:TiO2 and concentration of Co(II) dopant. The Fe3O4/TiO2-Co was characterized by FTIR, XRD, TEM, SEM-EDX, VSM, and SR UV-visible methods. Photoactivity of the Fe3O4/TiO2-Co was carried out using methylene blue as a target molecule in degradation reaction within a batch system. By using optimum conditions, the degradation of methylene blue solution was performed under exposure to UV, visible light and dark condition. Results showed that the Fe3O4/TiO2-Co formation was confirmed by the presence of Fe3O4 and anatase diffraction peaks in the X-ray diffractogram. SR UV-Vis spectra indicated that the Fe3O4/TiO2-Co was responsive to visible light. Band gap energy of the Fe3O4/TiO2-Co with dopant concentration of 1; 5; 10 and 15% were 3.22; 3.12; 3.09 and 2.81 eV, respectively. The methylene blue solution can be well photodegraded at a pH of 10 for 210 min. The Fe3O4/TiO2-Co has the highest ability to methylene blue photodegradation with dopant concentration of 10% gave degradation yield of 80.51 and 95.38% under UV and visible irradiation, respectively.


Author(s):  
Digvijay Verma ◽  
Vinay Kumar Singh ◽  
Rinku Bharati ◽  
Shyam Kishore ◽  
Seshu Lavania

In the present study, the cyanophycean diversity of the Lakhimpur-Khiri district, northern Uttar Pradesh, India, has been investigated for the first time. Algae samples were collected in plastic bottles and preserved in 3-4% formalin from Lakhimpur-Khiri district of northern Uttar Pradesh in different seasons from 2015 to 2016. The field photographs of the selected localities were also taken and the location of each site noted down. For the Microscopic study of Cyanophycean algae, the samples were stained with 1 % aqueous methylene blue solution according to the standard method. The observations and photomicrography were done with help of Nikon Labophot-11 microscope. A total of 31 cyanophycean algal taxa have been recorded from different water bodies of Lakhimpur-Khiri. These algal taxa belong to 14 genera and 9 families of the division Cyanophyata. Of these, Oscillatoria (7), Phormidium (4) and Lyngbya (3) are abundant.


Author(s):  
Tamio Fujiwara ◽  
Hiroshi Ohue ◽  
Takumi Urata

In order to enhance the mixing and reaction capabilities of micromixers and microreactors, we had proposed a novel system termed alternate pumping microreactor (APMR) and had demonstrated that the APMR could generate a thin-layered structure under a particular pumping condition. This flow pattern should enhance the abovementioned capabilities. In this paper, we visualized the dilution process of methylene blue solution with water in the APMR and established a method to obtained the concentration field from the captured image according to the relation between the methylene blue concentration and the saturation of the captured color. To assess the reaction field, visualization of the reaction of ferrous sulphate and potassium thiocyanate was adopted. These visualization results suggested that the APMR enhanced the mixing and reacting capabilities and the time and channel length required for the reaction to complete were two order orders of magnitude lesser than those in the case of the ordinary reactor.


2017 ◽  
Vol 30 (12) ◽  
pp. e3712 ◽  
Author(s):  
Tianchu Zhao ◽  
Rui Liu ◽  
Jiapeng Lu ◽  
Xiaolin Zhu ◽  
Xuhong Zhu ◽  
...  

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