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1.
Hydroxyapatite/titania nanocomposites of different ratios have been successfully synthesized by combined high gravity and hydrothermal methods. SEM and TEM observations showed that small spheres of TiO 2, identified as anatase crystals of 10–15 nm, were deposited on HAp rod-like crystals. EDAX analysis confirmed the presence of Ca, P, Ti and O. X-ray diffraction patterns indicated the presence of hydroxyapatite and anatase phase. More number of anatase peaks appeared in the XRD patterns with higher colloidal concentration of TiO 2 in the HAp/TiO 2 compound. Mechanical stability of the HAp/TiO 2 nanocomposites was determined by reinforcing them with high molecular weight polyethylene (HMWPE) and the tensile strength of the samples was analyzed. Photocatalytic activity of the HAp/TiO 2 particles was examined by decomposition of methyl orange (MO). The results showed that photocatalytic properties of HAp/TiO 2 composites are more effective than that of individual HAp and TiO 2 which implied that the HAp improved the photocatalytic activity of well known photocatalyst TiO 2. 相似文献
2.
The titania/hydroxyapatite composite granular photo-catalyst with novel microstructure was fabricated by the process based on the liquid immiscibility effect and followed by precalcination and hydrothermal treatment from commercially available powders of α-Tri-calcium phosphate and TiO 2. XRD, SEM, BET, optical microscopy and UV-vis spectrophotometer were applied to characterize the prepared photo-catalyst. Microstructure analysis indicated that the granule was weaved by rod-shaped hydroxyapatite crystals whose surface was covered by nano-sized TiO 2. In the composite granules, the active surface of anatase was retained effectively. With the hybridization of TiO 2 and HAp, a 16-nm blue-shift of absorption edge could be observed and the crystallinity of anatase could be enhanced by precalcination. The granules with the rod-shaped hydroxyapatite crystals performing as scaffold work as three-dimensional high porous, size-controllable small reactor. The phase and microstructure transformation of the granule before and after hydrothermal treatment was investigated and its decomposition ability was evaluated by using Methylene blue as a target pollutant compound. 相似文献
3.
Mesoporous anatase TiO 2 nanopowder was synthesised by the sol–gel method using ultrasonic irradiation. This method is simple and faster for the synthesis of phase pure mesoporous anatase TiO 2 nanopowder. The product is characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron spectroscopy (TEM), thermo gravimetric analysis, Brunauer–Emmett–Teller (BET) surface area, UV–visible diffuse reflectance spectroscopy and Fourier transform infrared spectroscopy. Analysis of XRD patterns, SEM and TEM image shows that the average particles size is of 19.9 nm and has an anatase structure. The mesoporous nature was determined by the BET method using the Barrett–Joyner–Halenda (BJH) model. 相似文献
4.
In this study, a good combination consisting of electrospun titanium dioxide (TiO 2) nanofibers incorporated with high purity hydroxyapatite (HAp) nanoparticles (NPs) and antimicrobial silver NPs is introduced for hard tissue engineering applications. The synthesized nanofibers were characterized by various state of art techniques like; SEM, XRD, TEM, TEM EDS and XPS analyses. SEM results confirmed well oriented nanofibers and good dispersion of HAp and silver NPs, respectively. XRD results demonstrated well crystalline feature of three components used for electrospinning. Silver NPs were having a diameter in range of 5–8 nm indicated by TEM analysis. Moreover, TEM EDS analysis demonstrated the presence of each component with good dispersion over TiO 2 nanofiber. The surface analyses of nanofibers were investigated by XPS which indicated the presence of silver NPs on the surfaces of nanofibers. The obtained nanofibers were checked for antimicrobial activity by using two model organisms E. coli and S. aureus. Subsequently, antimicrobial tests have indicated that the prepared nanofibers do posses high bactericidal effect. Accordingly, these results strongly recommend the use of obtained nanofiber mats as future implant materials. 相似文献
5.
Metal–ceramic nanocomposites have a special interest for biomedical applications such as in dental and bone implants. One interesting possibility to control the size of these materials is their fabrication on electrospun nanofibers. In this communication, we reported the use of bio-activated titanium oxide electrospun nanofibers as a template for the synthesis of hydroxyapatite (HAp) [Ca 10(PO 4) 6(OH) 2] crystals. Titanium oxide (TiO 2) nanofibers were fabricated using a viscous solution of titanium isopropoxide (TiP)/poly(vinyl acetate) (PVAc) via electrospinning and then chemically treated with NaOH followed by diluted HCl to explore the possibility of enhancing the bioactivity. Thus obtained nanofibers were employed for the simulated body fluid (SBF) mediated biomimatic synthesis of HAp crystals. The composites were characterized by different physico-chemical (FT-IR, XPS, XRD, SEM, and EDX) techniques. Results showed that the activated TiO 2 nanofibers served as an effective template for the assembly of plate like hydroxyapatite crystals. 相似文献
6.
TiO2 nanoparticles-deposited on hydroxyapatite (HAp) have been successfully synthesized by direct (single step) hydrothermal treatments of a CaCO3 suspension in a H3PO4 solution with 10 vol% TAS-FINE (titanium amine complex) at 150 degrees C for 6 h or 120 degrees C for 12-24 h under nearly neutral pH conditions. The obtained products were characterized by XRD, SEM-EDX, visible, Raman, and TEM. The XRD and Raman results showed the formation of HAp and TiO2 anatase phases under these hydrothermal conditions. SEM and TEM observations revealed that anatase TiO2 nanoparticles with the size of about 10 nm were deposited on the surfaces of the HAp crystals. 相似文献
7.
Pure anatase mesoporous TiO 2 nanospheres were synthesized by simple wet chemical treatment and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible spectroscopy (UV–vis), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction (XRD). The results revealed that the surface morphology of the TiO 2 spheres could be controlled by adjusting the concentration of N-methylaniline and that the average diameter of the TiO 2 spheres was 600 nm. FTIR results confirmed the formation of N-methylaniline capped TiO 2 nanospheres. 相似文献
8.
A novel approach was employed in the synthesis of high-dispersed anatase titania (TiO 2) nanocrystals by sol–gel process with NH 4NO 3 (AN) as solid substrates. Further calcination was conducted after the hydrous TiO 2 nanoparticles were adsorbed onto the surface of AN particles. The products were investigated by TGA, XRD, and TEM. The results indicated that AN was melting and decomposing during the calcining process, which was very important to inhibit the agglomeration of anatase TiO 2 nanocrystals. The highly dispersed anatase TiO 2 nanocrystals were in needle-shape having lengths about 16–20 nm and diameter of 6–9 nm. 相似文献
9.
Pure anatase TiO 2 nanoparticles were synthesized by microwave assisted sol–gel method and further characterized by powder X-ray diffraction
(XRD), energy dispersive x-ray analysis (EDAX), scanning electron microscopy (SEM), transmission electron microscopy (TEM),
and UV–Visible spectrophotometer, SEM images showed that TiO 2 nanoparticles were porous structure. The XRD patterns indicated that TiO 2 after annealed at 300 °C for 3 h was mainly pure anatase phase. The crystallite size was in the range of 20–25 nm, which
is consistent with the results obtained from TEM images. Microwave heating offers several potential advantages over conventional
heating for inducing or enhancing chemical reactions. 相似文献
10.
Nanocrystalline anatase films were prepared on glass substrates by the dip-coating method from aqueous refluxed sols and calcined
at 100, 300 and 500 °C. FT-IR, TEM, SEM, XRD, UV–VIS and XPS analysis were used to characterize the microstructure, phase
evolution and chemical composition of the refluxed sols (RS) sols and TiO 2 films. The photocatalytic activities of the TiO 2 films were evaluated by photocatalytic degradation of aqueous methyl orange solutions. It was found that the RS sols were
flavescent, alkalescent and contained anatase crystals. The TiO 2 thin films contained not only Ti and O elements, but also a small amount of N and Na elements. The TiO 2 films were transparent and its maximal light transmittance exceeded 80% under visible light region. Calcined at 300 °C, the
TiO 2 thin film showed the highest photocatalytic activity, when the calcination temperature is higher than 300 °C, the decrease
in photocatalytic activity is due to sintering and growth of TiO 2 crystallites resulting in the decrease of surface area. The results suggested that RS sols are promising novel precursors
for synthesizing TiO 2 films, and refluxing technique is quite efficient in preparing titania nanocrystalline films. 相似文献
11.
In this study, polymeric nanofibrous composites containing anatase TiO 2 short nanofibers (TiO 2-SNF) were successfully produced via electrospinning. The fabrication of the nanofibrous composite structure includes two steps. First, anatase TiO 2 nanofibers were obtained by calcination of electrospun PVP/TiO 2 nanofibers and then crushed into short nanofibers ranging from few microns in length. Second, these TiO 2-SNF were dispersed into polymer solutions and then electrospun into nanofibrous composites. We obtained nanofibers containing TiO 2-SNF from different polymer types including PMMA, PAN, PET and PC. The SEM and TEM imaging indicated that some of the TiO 2-SNF were fully covered by the polymeric matrix whereas some TiO 2-SNF were partially covered and/or stick on the surface of the fibers. The photocatalytic activity of nanofibrous composites containing TiO 2-SNF was evaluated by monitoring the photocatalytic decomposition of a model dye (rhodamine-6G) under UV irradiation. 相似文献
12.
Highly-active anatase TiO 2 nanorods have been successfully synthesized via a simple two-step method, hydrothermal treatment of anatase/rutile titanium dioxide nanoparticle powder in a composite-hydroxide eutectic system of 1:1 M KOH/NaOH, followed by acid post-treatment. The morphology and crystalline structure of the obtained nanorods were characterized using XRD, TEM, SEM/EDX and BET surface area analyzer. The obtained TiO 2 nanorods have a good crystallinity and a size distribution (about 4-16 nm); with the dimensions of 200-300 nm length and of 30-50 nm diameter. Compared with its precursor anatase/rutile TiO 2 nanoparticles and the titanate nanotubes, the pure anatase TiO 2 nanorods have a large specific surface area with a mesoporous structure. The photocatalytic performance of the prepared nanorods was tested in the degradation of the commercial Cibacrown Red (FN-R) textile dye, under UV irradiation. Single-crystalline anatase TiO 2 nanorods are more efficient for the dye removal. 相似文献
13.
In this paper, the focus is on understanding the properties of nanocomposite hydroxyapatite (HAp)/titania (TiO 2) thin films with respect to TiO 2 concentration. HAp/TiO 2 nanostructured composite thin films with different TiO 2 concentrations were successfully fabricated by a simple sol–gel dip coating method. Highly stable HAp and TiO 2 sols were prepared prior to the formation of nanocomposite thin films. The coatings were performed under controlled dipping and heat treatment processes. Phase pure HAp and TiO 2 were well developed in the nanocomposite after the heat treatment and this was confirmed by XRD. The SEM and AFM analyses of HAp/TiO 2 nanocomposite coatings show the variation in the morphology as a consequence different TiO 2 concentration. This shows a reduction in the particle size to nanoscale due to the addition of TiO 2. The mechanical strength of the coating also increased upon the addition of TiO 2 as determined by nanoindentation. The composite thin films with 50 and 80 vol.% of TiO 2 show good mechanical strength when compared to other concentrations of TiO 2. 相似文献
14.
Titanium dioxide (TiO 2) nanocrystals with specific exposed crystal facet have attracted considerable interest due to their promising applications in the fields of energy and environment. In this paper, we report on a simple solvothermal approach for the synthesis of anatase TiO 2 octahedra with high yield, using titanium(IV) sulfate and hydrazine hydrate as the starting materials. The formation mechanism of anatase TiO 2 octahedra is suggested. The samples were characterized with XRD, Raman, SEM, TEM, FTIR, XPS, and UV/vis techniques, and further tested as a candidate in photocatalysis to decompose methyl orange in aqueous solution at room temperature. The results show that SO 42− ions not only benefit the formation of octahedral nanocrystals, but also inhibit nitrogen doping into TiO 2 matrix. More importantly, it is found that the octahedral TiO 2 nanocrystals show enhanced photocatalytic activity compared to TiO 2 P25 and anatase TiO 2 counterparts. 相似文献
15.
Anatase TiO 2 thin films were successfully prepared on glass slide substrates via a sol–gel method from refluxed sol (RS) containing anatase TiO 2 crystals at low temperature of 100 °C. The influences of various refluxing time on crystallinity, morphology and size of the RS sol and dried TiO 2 films particles were discussed. These samples were characterized by infrared absorption spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission-scanning electron microscopy (FE-SEM) and UV–vis absorption spectroscopy (UV–vis). The photocatalytic activities of the TiO 2 thin films were assessed by the degradation of methyl orange in aqueous solution. The results indicated that titania films thus obtained were transparent and their maximal light transmittance exceeded 80% under visible light region. The TiO 2 thin films prepared from RS-6 sol showed the highest photocatalytic activity, when the calcination temperature is higher than 300 °C. The degradation of methyl orange of RS-6 thin films reached 99% after irradiated for 120 min, the results suggested that the TiO 2 thin films prepared from RS sol exhibited high photoactivities. 相似文献
16.
Different titanium oxide nanoparticles were formed through pulsed discharge of Ti wires in distilled water and H 2O 2 solution. The recovered samples were characterized by various techniques, such as XRD, SEM and TEM. The results confirm the presence of various titanium oxide nanoparticles including TiO 2 phases (anatase and rutile) and various nonstoichiometric TiO 2−x in recovered samples owing to the oxygen deficient circumstance through pulsed discharge. The titanium oxide nanoparticles exhibit a spherical shape with a size of 10–300 nm. The results show that the energy input adjusted by charging voltage is one major factor to control the phases of titanium oxide and the overall oxygen content of recovered samples. In addition, the H 2O 2 content in distilled water also affects the oxygen content of recovered samples. The sample recovered from 10% H 2O 2 solution is pure TiO 2 consisting of anatase and rutile without nonstoichiometric TiO 2−x. Moreover, the UV–Vis absorption spectra of recovered samples show their intensive visible light absorption and the correlation between the visible light absorption and the experimental conditions (charging voltage and H 2O 2 content). 相似文献
17.
Nanocrystalline particles of pure anatase titania were prepared by two different methods. One is the sol-gel method at ambient temperature using ultrasonication (TiO 2-SG-US) and conventional stirring method (TiO 2-SG-S) and the other by surfactant assisted hydrothermal synthesis (TiO 2-HT). More uniform distribution/dispersion of the nanoparticles (SEM), marginally higher surface area, better thermal stability and phase purity are some of the advantages of preparation of nanocrystalline titania by sol gel ultrasonication method and hydrothermal synthesis method. The behavior of anatase titania in photocatalytic decomposition of methylene blue in aqueous medium was studied as a function of the method of preparation and the crystallite size. The nanoparticles prepared by ultrasonication method were more effective than both, the sample prepared by conventional stirring method and commercial Degussa P-25. The higher photocatalytic activity of TiO 2-SG-US is attributed to the more uniform size of the particles as compared to TiO 2-SG-S samples. Both TEM and XRD data on TiO 2-HT samples reveal a uniform and nanocrystalline TiO 2 particles, which showed photocatalytic activity in both UV and visible region although brookite phase was also present. 相似文献
18.
Macroporous TiO 2 microspheres have been synthesized on a large scale by a facile hydrothermal process using titanium tetrachloride (TiCl 4) as the titanium source, ammonium fluoride (NH 4F) and hydrogen peroxide (H 2O 2) as the etchant. X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM) studies show that the anatase TiO 2 microspheres are well-crystalline with an average diameter of 5.43 μm. N 2 adsorption–desorption and mercury intrusion porosimetry analysis reveal that the as-prepared TiO 2 microspheres are composed of numerous pore networks with an average pore diameter of 274 nm and porosity of 39.8%. In addition, the formation mechanisms of macroporous TiO 2 microspheres were also investigated. 相似文献
19.
Well-aligned anatase and rutile TiO 2 nanorods and nanotubes with a diameter of about 80–130 nm have successfully been fabricated via sol-gel template method.
The prepared samples were characterized by using thermogravimetric (TG) and differential thermal analysis (DTA), X-ray diffraction
(XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy
(EDS). The XRD results indicated that the TiO 2 nanorods were crystallized in the anatase and rutile phases, after annealing at 400–800 °C for different periods of time
from 0.2 to 10 h. 相似文献
20.
Pure TiO2 and Cu–doped TiO2 containing different amounts of copper ions with anatase/rutile/brookite triphasic structure were successfully synthesized through a simple hydrothermal method. The obtained samples were characterized by X–ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), X–ray photoelectron spectroscopy (XPS), UV?vis diffuse reflectance spectroscopy (UV-DRS), photoluminescence spectroscopy (PL) and Brunauer–Emmett–Teller surface area analyze (BET). Both pure and Cu–doped TiO2 show relatively high photocatalytic activity owing to their considerable surface areas. Moreover, the three–phase coexisting structure and the conversion between Cu2+ and Cu+ ions facilitate the separation of photogenerated electrons and holes, which is favorable for photocatalytic performance. 1%Cu–TiO2 exhibits the highest photocatalytic activity and the degradation degree of rhodamine B (RhB) reaches 93.5% after 30 min, which is higher than that of monophasic/biphasic 1%Cu–TiO2. ·O2? radical is the main active species, and h+ and ·OH species are subsidiary in the degradation process. 相似文献
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