共查询到20条相似文献,搜索用时 15 毫秒
1.
Lu
i Marija Milosavljevi Nedeljko Radeti Maja aponji Zoran Radoi
i Marija Kalagasidis Krui Melina 《Polymer Composites》2014,35(4):806-815
Photocatalytic degradation of dye C.I. Acid Orange 7 in aqueous solution using TiO2/hydrogel nanocomposite under solar light simulating source was studied. Hydrogel based on chitosan, itaconic and methacrylic acid was modified with colloidal TiO2 nanoparticles synthetized by acidic hydrolysis of TiCl4 and commercial Degussa P25 TiO2 nanoparticles. SEM/EDX analysis confirmed the presence of TiO2 nanoparticles onto/into hydrogel. It was found that both types of photocatalysts efficiently removed the dye from solution, but sorption rates and photodegradation efficiency were higher in the case of colloidal TiO2 nanoparticles. They ensured complete discoloration of dye solution. The efficiency of the reused TiO2/hydrogel nanocomposite showed that photodegradation activity was maintained at satisfactory level after three repeated cycles of illumination. POLYM. COMPOS., 35:806–815, 2014. © 2013 Society of Plastics Engineers 相似文献
2.
《Ceramics International》2017,43(6):4866-4872
A unique Cu2O/TiO2 nanocomposite with high photocatalytic activity was synthesized via a two-step chemical solution method and used for the photocatalytic degradation of organic dye. The structure, morphology, composition, optical and photocatalytic properties of the as-prepared samples were investigated in detail. The results suggested that the Cu2O/TiO2 nanocomposite is composed of hierarchical TiO2 hollow microstructure coated by a great many Cu2O nanoparticles. The photocatalytic performance of Cu2O/TiO2 nanocomposite was evaluated by the photodegradation of methylene blue (MB) under visible light, and compared with those of the pure TiO2 and Cu2O photocatalysts synthesized by the identical synthetic route. Within 120 min of reaction time, nearly 100% decolorization efficiency of MB was achieved by Cu2O/TiO2 photocatalyst, which is much higher than that of pure TiO2 (26%) or Cu2O (32%). The outstanding photocatalytic efficiency was mainly ascribed to the unique architecture, the extended photoresponse range and efficient separation of the electron-hole pairs in the Cu2O/TiO2 heterojunction. In addition, the Cu2O/TiO2 nanocomposite also retains good cycling stability in the photodegradation of MB. 相似文献
3.
Boonsri Kusuktham 《应用聚合物科学杂志》2006,102(2):1585-1591
Preparation of interpenetrating polymer network (IPN) gel beads for dye absorption was carried out by using simultaneous crosslinking method. First, sodium alginate (SA), 3‐(methacrylamido) propyl trimethyl ammonium chloride (MAPTAC), and/or acrylamide (AM), K2S2O8, and N,N′‐methylenebisacrylamide (MBAM) were mixed in aqueous solution. The beads were prepared using K2S2O8 and MBAM as the initiator and crosslinking agent, respectively. Then, the solution was dropped into CaCl2 solution mixed with N,N,N′,N′‐tetramethylethylenediamine (TMEDA). The former was used as the crosslinking agent of alginate and the latter was used as the accelerator for the polymerization of monomer in the alginate solution. The gel bead composed of only alginate was also prepared to compare the properties with IPN gel bead. The components in IPN gel bead were examined by FTIR analysis. The factors effecting the particle size of alginate and IPN gel beads were investigated. In alginate gel bead, the concentration of solution affected the particle size, whereas type of monomer affected the particle size of IPN gel bead. The IPN gel bead had smooth surface (from SEM results), different from the alginate bead. Alginate content caused the swelling behavior of dried IPN beads. Cationic dye was absorbed by crosslinked alginate gel bead. The absorption of reactive dye by IPN gel bead was a result of its cationic charge. The absorption density of IPN gel beads was the reciprocal of the absorbent dosage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1585–1591, 2006 相似文献
4.
TiO2 nanoparticles were supported on a new persistent luminescence (3ZnO:Ga2O3:2GeO2):Cr3 + material. The sample was characterized by means of X-ray powder diffraction, scanning electron microscopy and radioluminescence. The photoactivity was evaluated for the degradation of methylene blue (MB) in aqueous solution especially in the darkness. A MB photodegradation occurred also in the absence of an external illumination. In fact, the persistent luminescence material stores and provides the necessary photons to the TiO2 allowing the photocatalysis process even in the darkness. 相似文献
5.
A dye‐sensitized indium tin oxide (ITO)/titanium dioxide (TiO2)/polyacrylonitrile (PAN)–propylene carbonate (PC)–lithium perchlorate (LiClO4)/graphite solar cell was fabricated, and its performance was tested in the dark and under the illumination of a 100 mW/cm2 light. Three TiO2 samples were used in the device, namely, uncoated TiO2, a TiO2 film coated with methyl red dye, and a TiO2 film coated with coumarin dye. The films were deposited onto an ITO‐covered glass substrate by a controlled hydrolysis technique assisted with a spin‐coating technique. The films were characterized by scanning electron microscopy to determine their average grain size. The smallest grain size (48 nm) was obtained for the uncoated film. An electrolyte of PAN–LiClO4 with PC plasticizer was prepared by a solution‐casting technique. A graphite electrode was prepared on a glass slide by an electron‐beam evaporation technique. The device showed rectification properties in the dark and showed a photovoltaic effect under illumination. The device with the uncoated TiO2 film showed the highest short‐circuit current density (2.0 μA/cm2) and an open‐circuit voltage of 0.64 V because it possessed the smallest grain size. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
6.
Photocatalysis of methylene blue on titanium dioxide nanoparticles synthesized by modified sol-hydrothermal process of TiCl4 总被引:1,自引:0,他引:1
Titanium dioxide nanoparticles were synthesized by the hydrolysis and condensation of TiCl4, an economic titanium precursor, in a mixed solvent of iso-propyl alcohol and water. As-prepared powders were characterized
by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM),
energy filtering transmission electron microscopy (EF-TEM). To examine the photocatalytic activity of the as-prepared TiO2, the photodegradation of MB which is a typical dye resistant to biodegradation has been investigated on TiO2 powders in aqueous heterogeneous suspensions. The photocatalytic activity of TiO2 powders prepared by the hydrolysis of TiCl4 in the mixed solutions of iso-PrOH/H2O exceeded that of commercial TiO2 powders. The apparent first order rate constants (k
app) for the photodegradation of methylene blue (MB) showed a good correlation with the absorbance area obtained by UV-VIS DRS
on wavelength in the limits of used lamp emission 300∼420 nm. 相似文献
7.
In this study, a sol–gel process was used to prepare hybrid nanocomposite consisting of octa(maleimidophenyl) silsesquioxane-silica/titania (maleimide–POSS (polyhedral oligomeric silsesquioxanes)–SiO2/TiO2) to use in methylene blue (MB) adsorption and as an antibacterial agent. The structure, surface, and morphological characteristics were confirmed through Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The optical and thermal stabilities were studied by conducting UV–visible and thermogravimetric analysis–differential scanning electron calorimetry analysis. The experimental results showed a maximum dye adsorption capacity of 92% achieved using 0.5?g of hybrid nanocomposite after 2.5?h at pH 9. We also investigated the effect that the adsorbent dosage, pH, and contact time had on the removal efficiency of the MB dye in aqueous solution. The recycling experiment showed a good adsorption capacity of the MB dye, even after five repeated cycles. Furthermore, the hybrid nanocomposite was tested against pathogenic bacteria, such as Bacillus cereus, Lactobacillus, Escherichia coli, and Pseudomonas aeruginosa. The nanocomposite was observed to be highly sensitive to E. coli, B. cereus, and P. aeruginosa, as confirmed by the size of the zone inhibition. 相似文献
8.
Vu Duc Chinh Le Xuan Hung Luca Di Palma Vu Thi Hong Hanh Giorgio Vilardi 《化学工程与技术》2019,42(2):308-315
A carbon nanotube (CNT)/gold nanoparticle (NP) nanocomposite was synthesized by simultaneously reducing the Au ions and depositing Au NPs on the surface of a CNT. The functional groups were investigated with Fourier transform infrared spectra. From the Raman spectra, the D‐band and G‐band of the CNT were identified. The deposition of nanometer‐sized Au NPs on the CNT sites was observed by transmission electron microscopy. The photodegradation of methylene blue (MB) in aqueous solutions was studied using various photocatalysts, including TiO2, TiO2‐SiO2, CNT/TiO2, CNT/TiO2‐SiO2, Au/TiO2, CNT‐Au/TiO2, and CNT‐Au/TiO2‐SiO2 composites. CNT addition leads to a synergic effect, improving the photoactivity of the catalysts. A possible physically based mechanism was proposed involving the reduction of electron‐hole recombination and fast electron‐transfer possibility. 相似文献
9.
《Ceramics International》2015,41(8):9671-9679
The present work is focused on the preparation of hybrid ZnO/TiO2/Ag2O nanocomposite for enhanced photocatalytic activity. The resultant samples are characterized by using XRD, SEM, EDX, HR-TEM, UV-DRS, BET and XPS techniques. X-ray diffraction analysis indicates the co-existence of wurtzite, anatase and cubic phases in ZnO/TiO2/Ag2O nanocomposite. The band gap energy value of the photocatalyst is 3.39 eV, which has been evidenced from UV–visible diffuse reflectance spectroscopy measurements. Photocatalytic degradation of methylene blue dye has been investigated by using UV–visible spectrophotometer. From the result, it has been concluded that ZnO/TiO2/Ag2O nanocomposite has proven to be an efficient photocatalyst under UV irradiation when compared to that of mono and binary oxide systems. Further, the possible photodegradation mechanism is proposed to support the enhancement of photocatalytic activity towards degradation of dyes. 相似文献
10.
Preparation of aerochitin‐TiO2 composite for efficient photocatalytic degradation of methylene blue
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
An aerochitin–titania (TiO2) composite was successfully synthesized and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, and N2 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–TiO2 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 TiO2 nanoparticles and aerochitin–TiO2 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
11.
《分离科学与技术》2012,47(14):2298-2304
The preparation of poly(methacrylic acid) modified chitosan microspheres (PMAA-GLA-CTS) and its application for the removal of cationic dye, methylene blue (MB), in aqueous solution in a batch system were described. The modified chitosan was characterized using FTIR and XPS analysis. The effects of the pH of the solution, contact time, and initial dye concentration were studied. The adsorption capacity of the microspheres for MB increased significantly after the modification as a large number of carboxyl groups were introduced. The equilibrium process was better described by the Langmuir rather than the Freundlich isotherm. According to the Langmuir equation, the maximum adsorption capacity was 1 g · g?1 for MB. Kinetic studies showed better correlation coefficients for a pseudo-second-order kinetic model, confirming that the sorption rate was controlled by a chemisorption process. Photocatalytic regeneration of spent PMAA-GLA-CTS using UV/TiO2 is effective. Further, the regenerated PMAA-GLA-CTS exhibits 90% efficiency for a subsequent adsorption cycle with MB aqueous solutions. 相似文献
12.
《Ceramics International》2023,49(4):5977-5985
The efficient TiO2 NTs/Sn3O4 photocatalysts were synthesized by the hydrothermal deposition of Sn3O4 on TiO2 nanotube arrays (TiO2 NTs), and the morphology, microstructure and photocatalytic property were adjusted by changing the alkali kind. The TiO2 NTs/Sn3O4 prepared with NaOH exhibited the outstanding photoelectric conversion and photocatalytic environment remediation/H2 evolution. The methylene blue (MB) dye and Cr(VI) could be removed by the as-prepared photocatalysts under visible light irradiation, and ?O2?/?OH radicals were the main active species for MB photodegradation. Furthermore, the high photocatalytic H2 evolution rate was as high as 6.49 μmol cm?2 h?1. The outstanding photocatalytic activity and stability of TiO2 NTs/Sn3O4 photocatalysts would exhibit attractive prospect in the wastewater remediation and electric energy/hydrogen generation. 相似文献
13.
Polymer/semiconductor oxide nanocomposite films have been intensively investigated for various applications. In this work, we reported a simple hydrothermal method to fabricate highly transparent poly(vinyl alcohol)/titanium dioxide (PVA/TiO2) nanocomposite films with enhanced visible-light photocatalytic activity. The as-prepared PVA/TiO2 nanocomposite films showed high optical transparency in the visible region even at a high TiO2 content (up to 40 wt.%). The determination of photocatalytic activity by photodegradation of methyl orange (MO) and colorless phenol showed that PVA/TiO2 nanocomposite films exhibited enhanced visible-light photocatalytic activity and excellent recycle stability. This work provided new insights into fabrication of polymer/TiO2 nanocomposites as high performance photocatalysts in waste water treatment. 相似文献
14.
Thou-Jen Whang Hsien-Yu Huang Mu-Tao Hsieh Jyun-Jen Chen 《International journal of molecular sciences》2009,10(11):4707-4718
Silver nanoparticles doped on titanium oxide (TiO2) were produced by laser-liquid interaction of silver nitrate (AgNO3) in isopropanol. Characteristics of Ag/TiO2 (Ag doped TiO2) nanoparticles produced by the methods presented in this article were investigated by XRD, TEM, SEM, EDX, and UV-Vis. From the UV-Vis measurements, the absorption of visible light of the Ag/TiO2 photocatalysts was improved (additional absorption at longer wavelength in visible light region) obviously. The photocatalytic efficiency of Ag/TiO2 was tested by the degradation of methylene blue (MB) in aqueous solution. A maximum of 82.3% MB degradation is achieved by 2.0 wt% Ag/TiO2 photocatalyst under 2 h illumination with a halogen lamp. 相似文献
15.
TiO2 nanoparticles were synthesized by the hydrolysis and condensation of TiCl4 in a mixed solvent of iso-propyl alcohol and water with or without ultrasound treatment. As-prepared powders were characterized
by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy filtering transmission electron microscopy
(EF-TEM), particle size analysis and BET surface area analysis. The specific surface area, thermal stability and crystallization
of the as-prepared samples treated with ultrasound were higher than those of samples treated without ultrasound. To examine
the photocatalytic activity of the as-prepared TiO2, the photodegradation of MB which is a typical dye resistant to biodegradation has been investigated on TiO2 powders in aqueous heterogeneous suspensions. The photocatalytic degradation of a aqueous solution of methylene blue shows
a remarkable increase when it is carried out with ultrasound in all cases. 相似文献
16.
K. Okada A. Yoshizawa Y. Kameshima T. Isobe A. Nakajima K. J. D. Mackenzie 《Journal of Porous Materials》2011,18(3):345-354
Two different mesoporous silicas (MPS) were synthesized by hydrothermal treatment in NaOH solution of two SiO2 sources. These were microporous silica (MicroPS) derived from selectively acid leached metakaolinite and tetraethylorthosilicate
(TEOS). The hydrothermal syntheses of the MPSs were performed at a ratio of SiO2/cetyltrimethyl- ammonium bromide (CTABr)/NaOH/H2O = 1/0.1/0.3/150. The specific surface areas (S
BET) of the MPSs from MicroPS (MPS(M)) and TEOS (MPS(T)) were 1070 and 1020 m2/g, respectively. Composites of MPS (75 mass%) with TiO2 (25 mass%) were prepared using both SiO2 and two commercial TiO2 powders, P25 and ST-01. The adsorption–desorption behavior of methylene blue (MB) by the four resulting composites and the
two MPSs alone was unique in showing partially reversible behavior. The maximum MB adsorption, observed in the composite of
ST-01 with MPS(M), designated (S/M), was 0.034 mmol/g. The rates of MB adsorption in the dark and photodecomposition under
UV illumination were considerably different for the four composites and two TiO2 powers, and followed the order ST-01 < S/T < P25 < P/T ≈ P/M ≪ S/M. The removal rate of MB by the composite S/M by adsorption
and photodecomposition was further enhanced by heating at 700 °C. Direct photodecomposition of MB without adsorption in the
dark was greatly enhanced in the composites, especially in that composed of MPS(M) and ST-01. 相似文献
17.
《Ceramics International》2022,48(10):13906-13913
This study prepares Fe3O4@Ag@TiO2 (FAT) particles via a solvothermal route, then thermally treats the particles over a temperature range from 300 to 500 °C in flowing nitrogen atmosphere to form Fe3O4@Ag@TiO2-xNx (x = 0.056 to 0.15) (FATN) core-shell composite particles. The FATN particles comprise an outermost TiO2-xNx shell of about 20–50 nm in thickness, a Brunauer-Emmett-Teller surface area of 103.2–152.5 m2/g, and a Barrett-Joyner-Halenda pore size of 12.9–30.2 nm. The particles show dye adsorption and visible-light photocatalysis against a model methylene-blue (MB) dye in water. For the FATN particles being treated at 400 °C, they show a dark adsorption of 54.8% and an additional visible-light photodegradation of 25.1% when using a dyed wastewater with an initial MB concentration of 5 × 10-6 M. This compares favorably to those being treated at other nitridation temperatures. The 500 °C-treated FATN particles yet exhibit a dark adsorption of 99.1% against the MB solution. Use of an external magnet can facilely recycle the composite particles. The recycled particles remain greater than 72% of their initial MB removal capability after use of five times. The intermediate Ag nanolayer can release Ag ions to the surrounding water medium through the mesoporous shell channel. The time-dependent Ag release appears to follow the Voigt-Maxwell model and reaches 0.764 ppm after 48 h, suggesting a long-time releasing efficacy. 相似文献
18.
《Ceramics International》2022,48(7):9434-9441
In this study, we investigated the effect of Ag addition on the photocatalytic reactivity of TiO2 nanoparticles (NPs). Controlled amounts of Ag were incorporated in TiO2 NPs using aerosol spray pyrolysis and subsequent calcination. Ag/TiO2 composite NPs containing different amounts of Ag (e.g., 0, 0.5, 1, 2, and 5 wt%) were successfully fabricated. The photodegradation performances of the as-prepared Ag/TiO2 composite NPs were tested using methylene blue (MB) solution under UV and visible light irradiation. Upon increasing the Ag content to 1 wt%, the resulting Ag/TiO2 composite NPs exhibited increased photocatalytic reactivity due to lowered bandgap energy, which promoted both charge generation and separation. However, when the Ag content exceeded 1 wt%, the photocatalytic reactivity of the resulting Ag/TiO2 composite NPs was considerably deteriorated due to the masking effect of the excess Ag on the reactive sites of TiO2. Hence, the incorporation of an optimized amount of Ag in the TiO2 matrix promotes the photocatalytic reactivity of Ag/TiO2 composite NPs by controlling their bandgap energy and charge generation and separation processes. These results could lead to the development of photodegradation active substances for water treatment in organic solutions. 相似文献
19.
《Ceramics International》2016,42(14):15861-15867
A visible light active photocatalyst, Ag/TiO2/MWCNT was synthesized by loading of Ag nanoparticles onto TiO2/MWCNT nanocomposite. The photocatalytic activity of Ag/TiO2/MWCNT ternary nanocomposite was evaluated for the degradation of methylene blue dye under UV and visible light irradiation. Ag/TiO2/MWCNT ternary nanocomposite exhibits (~9 times) higher photocatalytic activity than TiO2/MWCNT and (~2 times) higher than Ag/TiO2 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/TiO2 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/TiO2/MWCNT shows excellent photocatalytic stability. This work highlights the importance of Ag/TiO2/MWCNT ternary nanocomposite as highly efficient and stable visible-light-driven photocatalyst for the degradation of organic dyes. 相似文献
20.
Synthesis and photocatalytic performance of PVA/TiO2/graphene‐MWCNT nanocomposites for dye removal
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
TiO2/graphene‐MWCNT nanocomposite was prepared using solvothermal reaction for the effective distribution of TiO2 nanoparticles on carbonaceous materials. TiO2/graphene‐MWCNT nanocomposite was immobilized in poly(vinyl alcohol) (PVA) matrix for a convenient recovery after wastewater purification. MWCNT was incorporated in a nanocomposite not only to prevent the restacking of graphene but also to increase the electron transfer from TiO2. The detailed characterization of the nanocomposite was performed using SEM, EDX, XRD, XPS, and FTIR. The photocatalytic performance of PVA/TiO2/graphene‐MWCNT nanocomposite was investigated by UV spectroscopy on the basis of degradation of organic pollutants. PVA/TiO2/graphene‐MWCNT nanocomposite showed improved photocatalytic decomposition of more than 70% of residual dye left in case of using PVA/TiO2/graphene nanocomposite due to the improved electron transfer and the higher adsorption of organic pollutants. PVA/TiO2/graphene‐MWCNT nanocomposite was suitable as a promising material for the recyclable photocatalytic wastewater purification system. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40715. 相似文献