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1.
Micrometer‐sized structures consisting of TiO 2 nanoparticles were prepared using the sol–gel technique in combination with the structure‐directing agent triethanolamine (TEA). The interaction of the TEA with the hydrolyzed sol–gel products led to the formation of TEA titanate complexes, which then enabled the assembly of sol–gel‐precipitated nanosized powders. A subsequent thermal treatment of these powders resulted in the formation of micrometer‐sized structures consisting of TiO 2 anatase and rutile nanoparticles. To characterize the prepared powders, FTIR spectroscopy, XRD analysis, the Brunauer‐Emmett‐Teller method (s BET), UV–Vis spectrometry and electron microscopy (FE‐SEM, and TEM) were employed. The photocatalytic degradation of the azo dye known as methylene blue was monitored under UV and Vis irradiation and showed that the micrometer‐sized structures consisting of TiO 2 nanoparticles exhibited a similar photocatalytic activity to submicrometer‐sized structures consisting of TiO 2 nanoparticles prepared without TEA. 相似文献
2.
An aerochitin–titania (TiO 2) composite was successfully synthesized and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, and N 2 adsorption isotherms. The photocatalytic activity of the composite was investigated on the degradation of the model organic pollutant, methylene blue (MB) dye, under UV irradiation. The aerochitin–TiO 2 composite showed excellent adsorptive and photocatalytic activity with a degradation degree of 98% for MB. The first‐order rate constants for the photodegradation MB by TiO 2 nanoparticles and aerochitin–TiO 2 composite were found to be (3.49 ± 0.04) × 10 ?3 and (1.82 ± 0.02) × 10 ?2 min ?1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45908. 相似文献
3.
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
4.
A plasmonic composite, Ag@AgCl‐TiO 2/OREC, was prepared by sol–gel combing calcination technique, precipitation, and photoreduction method. Then, Ag@AgCl‐TiO 2/OREC/QCS composite microspheres were fabricated by an emulsification/chemical crosslinking method using quaternized chitosan and Ag@AgCl‐TiO 2/OREC as scaffolds materials, potassium persulphate as initiator and N,N′‐methylenebisacrylamide as crosslinker. The resulting materials were characterized by Fourier transform infrared spectrometer (FTIR), X‐ray diffraction (XRD), UV‐visible diffused reflectance spectra (UV–vis DRS), and scanning electron microscopy (SEM). SEM showed that the Ag@AgCl‐TiO 2/OREC/QCS composite microspheres had loose, rough surface, and spherical shape, with an average diameter of 15–45 μm. The Ag@AgCl‐TiO 2/OREC/QCS composite microspheres present good adsorption–photocatalytic activities in the degradation of methylene orange (MO) and 92.1% MO was degraded after irradiation for 180 min. The high photocatalysis activity was attributed to the combined results of the relative high adsorption capacity, loose structure, and the surface plasmon resonance of silver nanoparticles formed on the surface of AgCl. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44601. 相似文献
5.
A novel nanoscale GR–Nd/TiO 2 composite photocatalyst was synthesized by the hydrothermal method. Its crystal structure, surface morphology, chemical composition and optical properties were studied using XRD, TEM, and XPS, DRS and PL spectroscopy. It was found that graphene and neodymium modification shifts the absorption edge of TiO 2 to visible-light region. The results of photoluminescence (PL) emission spectra show that GR–Nd/TiO 2 composites possess better charge separation capability than do Nd/TiO 2 and pure TiO 2. The photocatalytic activity of prepared samples was investigated by degradation of methyl orange (MO) dye under visible light irradiation. The results show that the GR–Nd/TiO 2 composite can effectively photodegrade MO, showing an impressive photocatalytic activity enhancement over that of pure TiO 2. The enhanced photocatalytic activity of the composite catalyst might be attributed to the large adsorptivity of dyes, extended light absorption range and efficient charge separation due to Nd doping and graphene incorporation. 相似文献
6.
In this paper, a series of CdS/TiO 2 NTs have been synthesized by SILAR method. The as-prepared CdS/TiO 2 NTs have been analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectrometer (EDS), and ultraviolet–visible (UV–vis). And their photocatalytic activities have been investigated on the degradation of methylene blue under simulated solar light irradiation. XRD results indicate that TiO 2 NTs were anatase phase, CdS nanoparticles were hexagonal phase. FESEM results indicate that low deposition concentration can keep the nanotubular structures. UV–vis results indicate that CdS can be used to improve the absorbing capability of TiO 2 NTs for visible light, and the content of CdS affects the band gap. Photocatalytic results indicate that CdS nanoparticles are conducive to improve the photocatalytic efficiency of TiO 2 NTs, and the highest degradation rate can reach 93.8%. And the photocatalytic mechanism of CdS/TiO 2 NTs to methylene blue is also described. 相似文献
7.
As a new advanced oxidation technology, photocatalytic technology has broad application prospects in the field of wastewater treatment. However, in the actual use process, there will be difficulties in catalyst recovery and reuse. This article successfully prepared bacterial cellulose (BC) loaded silver and titanium dioxide nanoparticles (Ag-plated TiO 2/BC composite pellicle) by in situ embedding method. BC not only works as the carrier to load TiO 2 and Ag NPs but also adsorbs dyes to promote the reaction. As a reusable photocatalytic film, it is convenient to use and recycle in terms of testing and characterization compared with powders. The results show that Ag and TiO 2 nanoparticles were closely embedded in BC. We evaluated the photocatalytic degradation performance of the catalyst on methylene blue (MB), active red X-3B, and Rhodamine B. When the reaction time was 2 h, the dye removal rates were 71%, 68%, and 82.6%. At the same time, through the inhibition zone experiment, it was found that the material has a certain inhibitory effect on both Escherichia coli and Staphylococcus aureus. Therefore, the supported catalyst prepared by this method has the advantages of high catalytic activity, relatively stable property, easy recovery, and tailorability, making it potentially applicable in sewage post-treatment links. 相似文献
8.
The mechanical stability of titania (TiO 2) nanofibers was improved by fabricating TiO 2/poly(dimethyl siloxane) (PDMS) composite fibers using a combination of hybrid electrospinning and sol‐gel methods, followed by heat treatment at 250°C for 3 h. The compositions (90/10, 80/20, and 70/30, w/w) of the TiO 2/PDMS composite fibers were varied by adjusting the flow rate of the PDMS sol with the flow rate of TiO 2 sol fixed. There was no significant change in morphology and average diameter of the as‐spun TiO 2/PDMS fibers after heat treatment. Both the tensile strength and modulus of the TiO 2/PDMS composite fibers increased gradually with increasing PDMS content up to 30 wt %. In addition, from the photo‐degradation reaction of methylene blue, the photocatalytic activity of TiO 2/PDMS composite fibers was strongly dependent on the TiO 2 content (%) in the composite fibers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
9.
It is critical to develop an appropriate dye degrading technique to preserve the natural environment and human health owing to the dangerous water pollution caused by effluent dyes. So, in this work, a ZSM-5/TiO2/Ni photocatalyst was synthesized as a novel composite and used for degrading methylene blue dye in the solution. The sol–gel approach was used to immobilize titanium dioxide nanoparticles on the ZSM-5 surface, and the resulting photocatalyst was then modified using nickel nanoparticles to improve its photocatalytic performance. The nanocomposite was characterized using different tools such as FE-SEM, EDX, XRD, FT-IR, TGA, and UV–Vis spectrophotometer. The XRD confirmed that the synthesized composite has the characteristic TiO2 peaks. FE-SEM images of ZSM-5 exhibited rough, uneven, and jagged surfaces. A distinct shift in the morphology of the surface resulted when titanium dioxide was fully immobilized on the surface of ZSM-5. Shape complexity and surface roughness of the particles are elevated in the case of the ZSM-5/TiO2/Ni nanocomposite. The maximum % degradation of 50 mL of 15 mg/L of methylene blue dye is 99.17% and achieved at pH?=?8, irradiation time?=?140 min, and photocatalyst dosage?=?0.05 g. The synthesized composite can be regenerated and reused several times without losing its efficacy. 相似文献
10.
A new multifunctional nanocomposite based on poly (xanthoneamide-triazole-ethercalix) (PXTE) and TiO 2 nanoparticles (PXTE–TiO 2), which is a novel class of multiphase material containing nanosized inorganic material within polymer matrix, was prepared and characterized fully in this article. At first, PXTE was synthesized through click reaction, and then PXTE–TiO 2 nanocomposite was prepared by chemical immobilization of PXTE onto the modified TiO 2 nanoparticles. Nuclear magnetic resonance, Fourier transform infrared, X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, and thermal gravimetric analysis were applied for characterization of synthesized materials. Dye and ion removal capability of PXTE–TiO 2 nanocomposite were investigated by batch method for methylene blue and cadmium ion. The results showed that thermal stability and potential applicability of PXTE–TiO 2 nanocomposite make it as a good candidate for wastewater refinement. 相似文献
11.
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
12.
The TiO 2/SiO 2/Ni–Cu–Zn ferrite composite for magnetic photocatalysts with high photocatalytic activity is successfully prepared in this study. The composite are composed of spherical or elliptical Ni–Cu–Zn ferrite nanoparticles about 20–60 nm as magnetic cores, silica as barrier layers with thickness of 15 nm between the magnetic cores and titania shells with thickness approximately 1.5 nm. Photodegradation examination of TiO 2/SiO 2/ Ni–Cu–Zn ferrite composite was carried out in methylene blue (MB) solutions illuminated under a Xe arc lamp with 35 W and color temperature of 6000 K. The results indicated that about 47.1% of MB molecules adsorbed on the TiO 2/SiO 2/Ni–Cu–Zn ferrite composite within 30 min mixing due to it higher pore volume of 0.034 cm 3/g, and after 6 h Xe lamp irradiation, 83.9% of MB 16.1% was photodegraded. Compared with the TiO 2 /Ni–Cu–Zn ferrite composite, the TiO 2/SiO 2/Ni–Cu–Zn ferrite composite with silica barrier layer prohibited the photodissolution and enhanced the photocatalytic ability. The magnetic photocatalyst shows high photocatalytic efficiency that the apparent first‐order rate constant kobs is 0.18427 h ?1, and good magnetic property that the saturation magnetization ( Ms) of is 37.45 emu/g, suggesting the magnetic photocatalyst can be easily recovered by the application of an external magnetic field. 相似文献
13.
Novel composite film was synthesized by TiO 2 doping into phosphomolybdic acid (PMoA)/polyvinylpyrrolidone (PVP) system. The influence of TiO 2 doping on its microstructure and photochromic properties was investigated via atomic force microscopy, transmission electron microscope, Fourier transform infrared spectroscopy (FT‐IR), ultraviolet–visible spectra, and X‐ray photoelectron spectroscopy (XPS). After TiO 2 doping, the surface of TiO 2/PMoA/PVP composite film changed to rough from smooth, and the particle size significantly increased. The FT‐IR results verified that the basic structure of PMoA and PVP were not destroyed in the composite films. The non‐bonded interaction between the acid and polymer was strengthened by TiO 2 doping. Irradiated with UV light, composite films changed from colorless to blue. The TiO 2/PMoA/PVP composite film exhibited a strong photochromic effect and faster bleaching reaction than that of PMoA/PVP film. XPS results indicated that the amount of PMoA in photo‐reductive reaction was increased after TiO 2 doping, which resulted in the photochromic efficiencies enhanced. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41583. 相似文献
14.
1 H,1 H,2 H,2 H‐Perfluorooctyl trichlorosilane (PFTS) was used to modify TiO 2 nanoparticles, and hydrophobic PFTS–TiO 2 nanoparticles were obtained by an ultrasonic reaction method. The PFTS–TiO 2 surface morphological and hydrophobic properties were analyzed with scanning electron microscopy (SEM), Fourier transform infrared spectrometry, and contact angle (CA) testing. Then, the poly( p‐phenylene benzobisoxazole) fabric–phenolic composite filled with PFTS–TiO 2 as a lubricant additive was fabricated by a dip‐coating process. The tribological properties of the composite were investigated, and the wear surface morphology was observed by SEM. The experimental results show that the water CA of the composite filled with PFTS–TiO 2 was 158°, and the composite containing 4 wt % PFTS–TiO 2 exhibited excellent antifriction and abrasion resistance. The hydrophobic surface of the composite showed excellent durable performance with a static water CA of 126.7° after abrasion. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45077. 相似文献
15.
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
16.
Ag 2O modified TiO 2 nanoparticles were synthesized by precipitation and wet impregnation method. They were characterized by X-ray diffraction technique, UV-vis diffuse reflectance spectrophotometry and Fourier transform infrared spectroscopy. Inductively coupled plasma mass spectrometry was performed to quantify Ag amount in the photocatalysts. The photocatalysts occurred in the concentration range of 0.05%–2% in the Ag/Ti molar ratio. The photocatalytic activity was investigated for the degradation of methylene blue as a model organic dye. Optimum reaction conditions were determined to provide maximum dye degradation efficiencies under visible light. Under visible light illumination, C2-Ag 2O/TiO 2 (Ag/Ti = 0.1/100) showed the highest activity. Reaction rate constants were calculated and compared for various reaction conditions. 相似文献
17.
In the present study, titania nanoparticles were first constructed on mesoporous aluminosilicate Al-SBA-15 in supercritical carbon dioxide (Sc-CO 2) and the resultant samples were characterized by a combination of various techniques, such as X-ray diffraction (XRD), nitrogen physisorption, 27Al MAS NMR, UV–vis diffuse reflectance spectroscopy, and transmission electron microscopy (TEM). It was identified that the Al species incorporated samples retained structures similar to that of the parent SBA-15. In addition, the content of titania loading varied with reaction temperature and time in Sc-CO 2. As-synthesized TiO 2/Al-SBA-15 samples were evaluated in terms of photocatalytic decolorization of methylene blue in aqueous solutions. It was observed that all TiO 2/Al-SBA-15 samples showed satisfactory decolorization efficiency that was much higher than those of TiO 2/SBA-15 and commercial TiO 2 under identical conditions, which could be mainly attributed to the effective adsorption capability, resulting from the extension of specific surface area after substitution of Si species with Al species. 相似文献
18.
In this study the possibility of tailoring the textile nanocomposite materials based on the polyester fabric and TiO 2 nanoparticles that can simultaneously provide desirable level of antibacterial activity, UV protection, and self‐cleaning effects with long‐term durability was investigated. To enhance the binding efficiency of colloidal TiO 2 nanoparticles, the surface of polyester fabrics was activated by low‐pressure RF air plasma, and corona discharge at atmospheric pressure. Obtained functionalized textile materials provided maximum antibacterial efficiency against gram‐negative bacterium E. coli. High values of UV protection factor (UPF) indicate the maximum UV blocking efficiency (50+) of these fabrics. The results of self‐cleaning test with blueberry juice stains and photodegradation of methylene blue in aqueous solution confirmed excellent photocatalytic activity of TiO 2 nanoparticles deposited on the fiber surface. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers 相似文献
19.
The structure, physical characteristics and photocatalytic selective oxidation properties of nanometer‐size TiO 2 particles produced by a sol–gel method were studied by X‐ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), X‐ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and photocatalytic selective oxidation measurements. Analysis of the XRD results shows that sol–gel‐produced TiO 2 nanoparticles have the anatase structure at annealing temperatures ≤973 K, that the rutile structure begins to emerge at annealing temperatures ≥973 K and the particles have the pure rutile structure at 1023 K. DRS indicates that the obtained TiO 2 nanoparticles exhibit a blue shift with decreasing crystallite size. Analysis of the XPS results shows that the TiO 2 nanoparticles have a lot of oxygen vacancies. The EPR spectrum of TiO 2 at 77 K is composed of a strong isotropic EPR Surface‐Ti 3+ signal(I) at g = 1.926 and a weak broad Bulk‐Ti 3+ signal (II) at g = 1.987. Quantitative EPR indicates that both signals show a size and temperature dependence. Photocatalytic oxidation of cyclohexane into cyclohexanol with high selectivity and activity has been obtained by activation of molecular oxygen over sol–gel‐produced TiO 2 nanoparticles under mild conditions in dry solvent, which reveals that the quantum size effect and surface state effect of nanoparticles are key points for governing the selective photocatalytic reaction. The photocatalytic oxidation mechanism under dry solvent is different from that in aqueous solutions. Copyright © 2003 Society of Chemical Industry 相似文献
20.
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
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