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1.
The photocatalytic activity of TiO 2 and ZrO 2‐coated polyacrylonitrile (PAN) fibers was compared through the self‐cleaning of methylene blue and eosin yellowish. TiO 2 and ZrO 2 nanocrystals were successfully synthesized and deposited onto PAN fibers with photocatalytic self‐cleaning activity using the sol‐gel process at low temperature. The pristine and treated samples have been characterized by several techniques, such as scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, diffuse reflectance spectroscopy, X‐ray diffraction, and thermogravimetric analysis. The TiO 2 nanoparticles with 10–20 nm in size, and ZrO 2 with 20–40 nm have been synthesized to form dispersed particles on the fiber surface, which shows photocatalytic properties when exposed to UV–Vis light. The photocatalytic activity, tested by measuring the degradation of adsorbed methylene blue and Eosin Y. Photocatalytic activity of TiO 2‐coated fibers toward dyes degradation was higher than that of ZrO 2‐coated fibers. This preparation technique can be also applied to new fabrics to create self‐cleaning and UV irradiation protection properties in them. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
2.
The current study establishes the unprecedented involvement in the evolution and production of novel core–shell nanocomposites composed of nanosized titanium dioxide and aniline‐ o‐phenylenediamine copolymer. TiO 2@copoly(aniline and o‐phenylenediamine) (TiO 2@PANI‐ o‐PDA) core–shell nanocomposites were chemically synthesized in a molar ratio of 5:1 of the particular monomers and several weights of nano‐TiO 2 via oxidative copolymerization. The construction of the TiO 2@PANI‐ o‐PDA core–shell nanocomposites was ascertained from Fourier transform IR spectroscopy, UV–visible spectroscopy and XRD. A reasonable thermal behavior for the original copolymer and the TiO 2@PANI‐ o‐PDA core–shell nanocomposites was investigated. The bare PANI‐ o‐PDA copolymer was thermally less stable than the TiO 2@PANI‐ o‐PDA nanocomposites. The core–shell feature of the nanocomposites was found to have core and shell sizes of 17 nm and 19–26 nm, respectively. In addition, it was found that the addition of a high ratio of TiO 2 nanoparticles increases the electrical conductivity and consequently lowers the electrical resistivity of the TiO 2@PANI‐ o‐PDA core–shell nanocomposites. The hybrid photocatalysts exhibit a dramatic photocatalytic efficacy of methylene blue degradation under solar light irradiation. A plausible interpretation of the photocatalytic degradation results of methylene blue is also demonstrated. Our setup introduces a facile, inexpensive, unique and efficient technique for developing new core–shell nanomaterials with various required functionalities and colloidal stabilities. © 2018 Society of Chemical Industry 相似文献
3.
Silver and zirconium co‐doped and mono‐doped titania nanocomposites were synthesized and deposited onto polyacrylonitrile fibers via sol–gel dip‐coating method. The resulted coated‐fibers were characterized by X‐ray diffraction (XRD), scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, diffuse reflectance spectroscopy, thermogravimetric analysis, and BET surface area measurement. Photocatalytic activity of the TiO 2‐coated and TiO 2‐doped coated fibers were determined by photomineralization of methylene blue and Eosin Y under UV–vis light. The progress of photodegradation of dyes was monitored by diffuse reflectance spectroscopy. The XRD results of samples indicate that the TiO 2, Ag‐TiO 2, Zr‐TiO 2, and Ag‐Zr‐TiO 2 consist of anatase phase. All samples demonstrated photo‐assisted self‐cleaning properties when exposed to UV–vis irradiation. Evaluated by decomposing dyes, photocatalytic activity of Ag–Zr co‐doped TiO 2 coated fiber was obviously higher than that of pure TiO 2 and mono‐doped TiO 2. Our results showed that the synergistic action between the silver and zirconium species in the Ag‐Zr TiO 2 nanocomposite is due to both the structural and electronic properties of the photoactive anatase phase. These results clearly indicate that modification of semiconductor photocatalyst by co‐doping process is an effective method for increasing the photocatalytic activity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
4.
Electrospun polyamide‐6 membranes containing titanium dioxide (TiO 2) photocatalyst were prepared and characterized. By tailoring the electrospinning parameters it was possible to obtain membranes having two different thicknesses, namely 5 and 20 µm, in which TiO 2 particles were homogeneously dispersed. As a comparison, hybrid films made with polyamide‐6 matrix and TiO 2 filler were successfully produced, with inorganic/organic ratios of 10 and 20 wt%. The photocatalytic activity of both hybrid systems was evaluated by following the degradation of methylene blue as a target molecule as a function of UV irradiation time. A smoother degradation was recorded for the electrospun membranes with respect to the hybrid films probably due to a less exposed surface because of the highly porous structure. Even if a longer photodegradation time was necessary, the degradation of the dye was successfully achieved. Copyright © 2010 Society of Chemical Industry 相似文献
5.
A visible light active photocatalyst, Ag/TiO 2/MWCNT was synthesized by loading of Ag nanoparticles onto TiO 2/MWCNT nanocomposite. The photocatalytic activity of Ag/TiO 2/MWCNT ternary nanocomposite was evaluated for the degradation of methylene blue dye under UV and visible light irradiation. Ag/TiO 2/MWCNT ternary nanocomposite exhibits (~9 times) higher photocatalytic activity than TiO 2/MWCNT and (~2 times) higher than Ag/TiO 2 binary nanocomposites under visible light irradiation. The enhancement in the photocatalytic activity is attributed to the synergistic effect between Ag nanoparticles and MWCNT, which enhance the charge separation efficiency by Schottky barrier formation at Ag/TiO 2 interface and role of MWCNT as an electron reservoir. Effect of different scavengers on the degradation of methylene blue dye in the presence of catalyst has been investigated to find the role of photogenerated electrons and holes. Simultaneously, the Ag/TiO 2/MWCNT shows excellent photocatalytic stability. This work highlights the importance of Ag/TiO 2/MWCNT ternary nanocomposite as highly efficient and stable visible-light-driven photocatalyst for the degradation of organic dyes. 相似文献
6.
Graphene/carbon composite nanofibers (CCNFs) with attached TiO 2 nanoparticles (TiO 2–CCNF) were prepared, and their photocatalytic degradation ability under visible light irradiation was assessed. They were characterized using scanning and transmission electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible diffuse spectroscopy. The results suggest that the presence of graphene embedded in the composite fibers prevents TiO 2 particle agglomeration and aids the uniform dispersion of TiO 2 on the fibers. In the photodegradation of methylene blue, a significant increase in the reaction rate was observed with TiO 2–CCNF materials under visible light. This increase is due to the high migration efficiency of photoinduced electrons and the inhibition of charge–carrier recombination due to the electronic interaction between TiO 2 and graphene. The TiO 2–CCNF materials could be used for multiple degradation cycles without a decrease in photocatalytic activity. 相似文献
7.
The effect of UV irradiation and micro‐ and nano‐TiO 2 as well as titanate nanotubes (TiNT) on the phase morphology and thermal properties of the electrospun PCL composite fibers was investigated. Polycaprolactone (PCL)/TiO 2 (micro‐ and nano‐TiO 2 as well as titanate nanotubes) composite fibers were prepared by electrospinning a polymer solution. The PCL and PCL/TiO 2 composite fibers were exposed to UV light at irradiation times of 5 and 10 days. After UV irradiation the crystallinity of the electrospun PCL/TiNTcomposite fibers increased because of the large specific surface area of TiNT. The thermal stability of the PCL/TiNT electrospun composite fibers increased due to the formation of crosslinking structure after UV irradiation. The SEM analysis suggests that after UV radiation the fibers showed high degree of degradation due to the high number of fibers breakages and fibers surface voids. The results of FTIR spectroscopy confirmed that the TiO 2 particles enhance the degradation process because of their photocatalytic activity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43539. 相似文献
8.
BiVO 4/TiO 2 nanocomposites were successfully synthesized by coupling the modified sol-gel method with hydrothermal method. The samples were physically characterized X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer, Emmett and Teller (BET)-specific surface area, UV–vis diffuse reflectance spectrophotometry, zeta potential, and photoluminescence techniques. The BiVO 4/TiO 2 nanocomposites exhibited good photocatalytic activity in degradation of methylene blue under simulated solar light irradiation. The photodegradation of methylene blue demonstrated that 0.5BiVO 4/0.5TiO 2 photocatalyst exhibited much enhanced photoactivity than pure BiVO 4 and TiO 2. Based on the obtained results, the as-prepare BiVO 4/ TiO 2 nanocomposite possessed great adsorptivity of methylene blue, extended light adsorption range, and efficient charge separation properties. Overall, this work could provide new insights into the fabrication of a BiVO 4/TiO 2 composite as high performance photocatalyst and promise as a solar light photocatalyst for dye wastewater treatment. 相似文献
9.
TiO 2 microspheres were successfully synthesised by simple solution phase method by using various amount of titanium butoxide as precursor. The prepared TiO 2 were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance absorption spectra (UV-DRS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). XRD analysis revealed that the as-synthesized TiO 2 microsphere poses an anatase phase. The photocatalytic degradation experiments were carried out with three different dyes, such as methylene blue, brilliant black, reactive red-120 for four hours under UV light irradiation. The results show that TiO 2 morphology had great influence on photocatalytic degradation of organic dyes. The experimental results of dye mineralization indicated the concentration was reduced by a high portion of up to 99% within 4 hours. On the basis of various characterization of the photocatalysts, the reactions involved to explain the photocatalytic activity enhancement due to the concentration of titanium butoxide and morphology include a better separation of photogenerated charge carriers and improved oxygen reduction inducing a higher extent of degradation of aromatics. 相似文献
10.
Anatase TiO 2 coatings prepared by solvothermal process in a neutral ethanol solution of isopropyl titanate at 160 °C have been grown on slag wool fibers (SWF) which were modified by hexadecyltrimethylammonium bromide (CTAB) in advance. X-ray diffraction patterns confirmed the coatings are of a nanocrystalline anatase structure, and scanning electron microscopy observations and energy-dispersive X-ray spectrum revealed a continuous coverage of TiO 2 formed on the fiber surfaces. The photocatalytic activity of the samples was tested by the photocatalytic degradation of methylene blue (MB) solution. The results show that CTAB modified slag wool fibers (CMSWF) are not a suitable adsorbent for MB due to their weaker negative surface charges. Anatase TiO 2 coated CMSWF display higher photocatalyst activity than anatase TiO 2 coated SWF without CTAB modification, and Anatase TiO 2 coated CMSWF are relatively stable under UV-light irradiation. 相似文献
11.
Mesoporous titanium dioxide (TiO2) photocatalysts were synthesized via a solvothermal method using sodium dodecyl sulfate (SDS) as templates. The effect of the SDS concentration and solution pH value on the resulting TiO2 catalyst and its photocatalytic activity were studied. The photocatalytic activity was assessed by degradation methylene blue under low-power (8W?×?4) UV light irradiation. The best performance showed that over 95% of methylene blue was degraded in 120 min and in the presence of S20 (20 mmol SDS addition, pH?=?4). With the optimal addition of SDS, the crystal size was reduced, and the surface area was increased. In addition, some bidentate-sulfates (–SO42?) residues were observed within the prepared mesoporous TiO2. The Detail characterization of of the as-prepared TiO2 samples were conducted by X-ray diffraction, Ultraviolet–Visible Spectroscopy, Scanning electron microscope, Brunauer-Emmett-Teller analysis, and Fourier-transform infrared spectroscopy, respectively. 相似文献
12.
In the present work, nanostructured TiO 2 films were prepared by electrochemical anodization process of titanium in fluoride-containing electrolytes using an innovative approach. After anodization, the TiO 2 films were annealed at 480?°C for 2 h in air in order to acquire anatase phase transformation and increase its crystallinity. The effects of anodization voltage, electrolyte concentration and anodization time on the formation of TiO 2 films and the photocatalytic degradation of methylene blue (MB) were discussed in details. The phase structure and surface morphology of the samples characterized by means of X-ray diffraction and scanning electron microscope. The as-prepared nanostructured TiO 2 film anodized in 0.5% HF electrolyte at 15 V for 240 min showed excellent photocatalytic degradation of MB and is promising for environmental purification. 相似文献
13.
In this study, bismuth oxyiodide/titanium dioxide (BiOI/TiO 2) heterostructures with different molar ratios of Bi and Ti were synthesized by electrospinning and hydrothermal methods. The samples thus synthesized were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), high-resolution TEM, X-ray photoelectron spectroscopy, and ultraviolet–visible diffuse reflectance spectroscopy. The results confirmed the presence of the BiOI/TiO 2 heterojunction with Bi/Ti molar ratios of 0.20–1 by electrospinning and hydrothermal methods. Photocatalytic activity was also evaluated by the degradation of methylene blue (MB) under visible-light irradiation. The 80% BiOI/TiO 2 heterostructure exhibited the best photocatalytic activity for the degradation of MB under visible-light irradiation. 相似文献
14.
Nanostructured titania has been extensively investigated for photocatalytic applications. Persistent challenge yet is how to effectively promote adhesion of microorganisms on the material surface for consequent enhanced photocatalytic disinfection. Here we report fabrication and characterization of titania-based nanocomposite coatings with addition of hydroxyapatite-reduced graphene oxide (HA-rGO). The nano features of TiO 2, HA, and rGO were well retained during liquid flame spray deposition. Photocatalytic activities of the coatings were examined by degradation of methylene blue and sterilization testing of Escherichia coli bacteria. Addition of HA-rGO effectively increased the specific surface area of the coatings and markedly enhanced adherence of the bacteria for subsequent extinguishment. The TiO 2–10 wt.% (HA-rGO) coating showed the best photocatalytic performances and further overloading of HA-rGO resulted in enwrapping of TiO 2 particles, resulting in deteriorated degradation activity. The results give clear insight into fabrication of novel photocatalytic nanocomposites by suspension thermal spray route for enhanced performances. 相似文献
15.
In this paper, we reported a “green” and facile method for one-pot solvothermal synthesis of carbon dots (CDs)/Ag nanoparticles (AgNPs)/titanium dioxide (TiO 2, commercial Degussa P25) ternary nanocomposites with enhanced photocatalytic performance. The characterizations of this ternary photocatalyst were studied at length and our results revealed that the crystalline phase of TiO 2 component remained unchanged after the reaction. While the newborn AgNPs and CDs were tightly attached onto the surface of TiO 2 nanoparticles. The photocatalytic activities of photocatalysts were tested by measurements of photo-degradation on methylene blue (MB) under ultraviolet (UV) and visible light. It was showed that the photocatalytic performance of the ternary photocatalyst was superior to that of single TiO 2 or CDs/TiO 2 binary photocatalyst. It was probably attributed to the synergistic effect of the photoelectrical properties of CDs and the surface plasmon resonance (SPR) effect of AgNPs, which could both enhance the absorption of visible light and hinder the recombination of photogenerated electron-hole pairs. 相似文献
16.
Application of brown titanium dioxide (TiO 2-x) and its modified composite forms in the photocatalytic decomposition of organic pollutants in the environment is a promising way to provide solutions for environmental redemption. Herein, we report the synthesis of effective and stable TiO 2-x nanoparticles with g-C 3N 4, RGO, and multiwalled carbon nanotubes (CNTs) using a simple hydrothermal method. Among all the as-synthesized samples, excellent photocatalytic degradation activity was observed for RGO-TiO 2-x nanocomposite with high rate constants of 0.075 min ?1, 0.083 min ?1 and 0.093 min ?1 for methylene blue, rhodamine-B, and rosebengal dyes under UV–Visible light irradiation, respectively. The altered bandgap (1.8 eV) and the large surface area of RGO-TiO 2-x nanocomposite impacts on both absorption of visible light and efficiency of photogenerated charge electron (e ?)/hole (h +) pair separation. This resulted in enhanced photocatalytic property of carbon-based TiO 2-x nanocomposites. A systematic study on the influence of different carbon nanostructures on the photocatalytic activity of brown TiO 2-x is carried out. 相似文献
17.
SnO 2 doped TiO 2 electropsun nanofiber photocatalysts were successfully prepared by means of electrospinning process. The surface morphology, structure and optical properties of the resultant products were characterized by field-emission electron microscopy (FE-SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy, photoluminescence (PL) and cathodoluminescence (CL) techniques. The utilized physiochemical analyses indicated that the introduced SnO 2 doped TiO 2 nanofibers have a smooth surface and uniform diameters along their lengths. The photocatalytic performance of the composite nanofibers was tested for degradation of methylene blue (MB) and methyl orange (MO) dye solution under ultraviolet (UV) irradiation. Under the UV irradiation, the photocatalytic reaction rate in case of utilizing SnO 2-doped TiO 2 nanofibers was rapidly increased than that of the pristine TiO 2 nanofibers. Overall, this study demonstrates cheap, stable and effective material for photocatalytic degradation at room temperature. 相似文献
18.
The heterogeneous titanium oxide-reduced graphene oxide-silver (TiO 2/RGO/Ag) nanocomposites were successfully prepared by incorporation of two dimensional (2D) RGO nanosheets and spherical silver nanoparticles (NPs) into the 1D TiO 2 nanofibers. The novel TiO 2/RGO/Ag nanocomposites were synthesized by loading TiO 2 nanofibers, prepared via electrospinning technique, on the RGO/Ag platform. The resulting nanocomposites have been characterized using various techniques containing transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and ultra-violet-visible (UV–vis) spectroscopy. Microscopic studies clearly verified the existence of TiO 2 nanofibers with Ag NPs on the surface of RGO sheet and formation of TiO 2/RGO/Ag nanocomposites. Moreover, the results of UV–vis spectroscopy demonstrated that TiO 2/RGO/Ag nanocomposites extended the light absorption spectrum toward the visible region and significantly enhanced the visible-light photocatalytic performance of the prepared samples on degradation of rhodamine B (Rh. B) as a model dye. It was found that, incorporation of 50 µl RGO/Ag into the TiO 2 nanofibers lead to a maximum photocatalytic performance. Also, the improvement of the inactivation of Escherichia coli ( E. coli) bacteria under visible-light irradiation was revealed by introduction of RGO/Ag into the TiO 2 matrix. The significant enhancement in the photo and bio-activity of TiO 2/RGO/Ag nanocomposites under visible-light irradiation can be ascribed to the RGO/Ag content by acting as electron traps in TiO 2 band gap. 相似文献
19.
TiO 2 nanowire/nanotube electrodes were synthesized by anodization of titanium foils in ethylene glycol solution containing 0.5 wt% NH 4F and 1 wt% water at 60 V for 6 h. The microstructure and morphology of the asprepared electrodes were investigated by XRD and SEM. A possible formation mechanism and oxidation parameters of nanocomposite structure were discussed. The relationship between structural characteristics of TiO 2 nanowire/nanotube electrodes and its photoelectrochemical characterization were evaluated by electrochemical analyzer and photocatalytic degradation of methylene blue (MB) solution. Furthermore, these TiO 2 nanowire/nanotube electrodes promoted the photoelectrochemical characterization due to the larger surface areas, enhanced light harvesting and electron transport rate. The results show that photocurrent density of 1.44mA/cm 2 and photocatalytic degradation of 95.51% was achieved for TiO 2 nanowire/nanotube electrodes, which were 0.55mA/cm 2 and 20.52% higher than the TiO 2 nanotube electrodes under a similar condition, respectively. 相似文献
20.
Highly ordered TiO 2 and WO 3–TiO 2 nanotubes were prepared by one-step electrochemical anodizing method and cobalt has been successfully deposited on these nanotubes by photo-assisted deposition process. The morphology, crystal structure, elemental composition and light absorption capability of samples were characterized by field emission scanning electron microscope, X-ray diffraction, energy dispersive X-ray spectrometer and ultraviolet–visible spectroscopy methods. All cobalt loaded samples show an appearance of red shift relative to the unloaded samples. The degradation of methylene blue was used as a model reaction to evaluate the photocatalytic activity of these novel visible-light-responsive photocatalysts. Results showed that the photocatalytic activity of bare WO 3–TiO 2 samples is higher than that with undoped TiO 2 sample. Compared with unmodified TiO 2 and WO 3–TiO 2, the Co/TiO 2 and Co/WO 3–TiO 2 samples exhibited enhanced photocatalytic activity in the degradation of methylene blue. Kinetic research showed that the reaction rate constant of Co/WO 3–TiO 2 is approximately 2.26 times higher than the apparent reaction rate constant of bare WO 3–TiO 2. This work provides an insight into designing and synthesizing new TiO 2–WO 3 nanotubes-based hybrid materials for effective visible light-activated photocatalysis. The catalysts prepared in this study exhibit industrially relevant interests due to the low cost and high photocatalytic activity. 相似文献
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