共查询到20条相似文献,搜索用时 0 毫秒
1.
Wei Xie Xinyan Xiao Yichao Zhao Weiping Zhang 《Journal of Coatings Technology and Research》2017,14(5):1147-1158
TiO2/MoS2 composite was encapsulated by hydrophobic SiO2 nanoparticles using a sol–gel hydrothermal method with methyltriethoxysilane (MTES), titanium tetrachloride (TiCl4), and molybdenum disulfide (MoS2) as raw materials. Then, a novel dual functional composite film with hydrophobicity and photocatalytic activity was fabricated on a glass substrates via the combination of polydimethylsiloxane adhesives and hydrophobic SiO2@(TiO2/MoS2) composite particles. The influence of the mole ratios of MTES to TiO2/MoS2 (M:T) on the wettability and photocatalytic activity of the composite film was discussed. The surface morphology, chemical compositions, and hydrophobicity of the composite film on the glass substrate were investigated by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and water contact angle (water CA) measurements. The results indicated that the composite film exhibited stable superhydrophobicity and excellent photocatalytic activity for degradation of methyl orange (MO) even after five continuous cycles of photocatalytic reaction when M/T was 7:1. The water CA and degradation efficiency for MO remained at 154° and 94%, respectively. Further, the composite film showed a good non-sticking characteristic with the water sliding angle (SA) at about 4°. The SiO2@(TiO2/MoS2) composite consisting of hydrophobic SiO2 nanoparticles and TiO2/MoS2 heterostructure could provide synergistic effects for maintaining long-term self-cleaning performance. 相似文献
2.
Zhixiong Zhou Lihua Zhu Jing Li Heqing Tang 《Journal of Applied Electrochemistry》2009,39(10):1745-1753
Uniform TiO2/SiO2 composite films were prepared on ITO substrates by electrodeposition, and highly photoelectrocatalytic (PEC) activity of
the composite films was observed toward the degradation of methyl orange (MO) in aqueous solutions. It was further found that
their PEC activity was dependent on the electrodeposition parameters including deposition time, solution pH and SiO2 content. Under the optimized condition, the PEC degradation of MO on TiO2/SiO2 composite film electrode could be enhanced about 14 times relative to that on neat TiO2 film electrode. The high PEC activity of the TiO2/SiO2 composite film electrode was mainly attributed to the enhancement of the charge separation of photo-generated electron-hole
pairs by the dispersion of SiO2 nanoparticles in the TiO2 matrix with the aid of the applied electric field. 相似文献
3.
PSA [poly-(styrene-methyl acrylic acid)] latex particle has been taken into account as template material in SiO2 hollow spheres preparation. TiO2-doped SiO2 hollow spheres were obtained by using the appropriate amount of Ti(SO4)2 solution on SiO2 hollow spheres. The photodecomposition of the MB (methylene blue) was evaluated on these TiO2-doped SiO2 hollow spheres under UV light irradiation. The catalyst samples were characterized by XRD, UV-DRS, SEM and BET. A TiO2-doped SiO2 hollow sphere has shown higher surface area in comparison with pure TiO2 hollow spheres. The 40 wt% TiO2-doped SiO2 hollow sphere has been found as the most active catalyst compared with the others in the process of photodecomposition of
MB (methylene blue). The BET surface area of this sample was found to be 377.6 m2g−1. The photodegradation rate of MB using the TiO2-doped SiO2 catalyst was much higher than that of pure TiO2 hollow spheres. 相似文献
4.
Khadijeh Beigom Ghoreishi Nilofar Asim Zatil Amali Che Ramli Zeynab Emdadi M. Ambar Yarmo 《Journal of Porous Materials》2016,23(3):629-637
Recent improvements in the performance of photocatalysts made it possible to tackle pollution through environment friendly methods. This study investigates the modification of the photocatalytic activity of TiO2 by employing WO3 and conductive polymers, namely, polyaniline (Pani) and polypyrrole (Ppy). Basing on our previous improvement of TiO2 using a conductive polymer and activated carbon (AC), this study determines the activated carbon forms of TiO2. The prepared composites are characterized using X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared, thermogravimetric analysis, Brunauer–Emmet–Teller, and UV–Vis spectroscopy. The specific surface area of the mesoporous composites is as follows: WO3/TiO2·AC (Pani) > WO3/TiO2·AC (Ppy) > WO3/TiO2·Pani > WO3/TiO2·Ppy (127 > 98 > 68 > 44 m2 g?1), which exhibited a similar trend to the photocatalytic performances (100 > 95 > 91 > 72 % conversion rate). This result could be attributed to higher porosity, surge of charge separation, and photo-responding range extension induced by the synergistic effect of WO3, conducting polymers, and TiO2 in the samples. 相似文献
5.
Nanoparticles of SiO2 or TiO2 have been added in the preparation of heat-resisting concretes of two types. The major technical and chemical characteristics
have been determined. Features have been found in some of the technological operations in making the concretes of both types,
and also aspects of the physicomechanical properties. Higher chemical stability has been found for heat-resisting concrete
containing TiO2 nanoparticles in an NaOH solution. 相似文献
6.
Mouza Al Ruqaishy Faisal Al Marzouqi Kezhen Qi Shu-yuan Liu Sreejith Karthikeyan Younghun Kim Salma Mohamed Zahran Al-Kindy Alex Tawanda Kuvarega Rengaraj Selvaraj 《Korean Journal of Chemical Engineering》2018,35(11):2283-2289
TiO2 microspheres were successfully synthesised by simple solution phase method by using various amount of titanium butoxide as precursor. The prepared TiO2 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 TiO2 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 TiO2 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
7.
Firstly, preparation of porous polyvinyl alcohol (PVA) spheres were investigated in detail by phase inversion method using N,N-dimethylacetamide (DMAc) and polyvinylpyrrolidone (PVP) as pore-forming additives. The morphology and pore structure of PVA spheres were characterized by SEM and BET measurements. It was found that the addition of DMAc and PVP increased the pore volume and the surface pore size of PVA sphere respectively. The maximum surface area of the porous PVA sphere reached 220 m2/g. Secondly; the synthesis of photoactive TiO2 NPs (anatase type) at the low temperature was developed by controlling the aging process of the TiO2 precursors. The crystallinity and photoactivity of TiO2 NPs increased with the aging time. Finally, TiO2 NPs/PVA composite spheres were prepared by immersing PVA sphere into TiO2 precursor solution. Their structures were characterized by XRD pattern, TEM and TGA measurement. It was found that TiO2 NPs were successfully immobilized into PVA spheres. The photodegradation of methyl orange (MO) under UV light by TiO2/PVA spheres showed a good photocatalytic efficiency. Moreover, TiO2/PVA spheres can be easily regenerated by the repeated immersion process. Overall, the porous TiO2/PVA sphere displays a good photoactive property and an advantage of easier recovery, which facilitates its application in large-scale wastewater treatment. 相似文献
8.
Characteristics and photocatalytic degradation of methyl orange on Ti-RH-MCM-41 and TiO<Subscript>2</Subscript>/RH-MCM-41 总被引:1,自引:0,他引:1
Surachai Artkla Kitirote Wantala Bang-orn Srinameb Nurak Grisdanurak Wantana Klysubun Jatuporn Wittayakun 《Korean Journal of Chemical Engineering》2009,26(6):1556-1562
Our purpose was to synthesize, characterize and test photodegradation of methyl orange on two catalysts containing 10 wt%
titanium supported on mesoporous MCM-41 synthesized with rice husk silica. The first catalyst was Ti-RH-MCM-41 prepared by
adding tetrabutyl orthotitanate (TBOT) in a synthetic gel of RH-MCM-41, and the second catalyst was TiO2/RH-MCM-41 prepared by grafting TBOT on the preformed RH-MCM-41. The mesoporous structures were observed on both catalysts
and they had surface area of 1,073 and 1,006 m2/g. The Ti in Ti-RH-MCM-41 was in the form of Ti(IV) with tetrahedral geometry residing in the mesoporous structure. This
form was less active for photodegradation of methyl orange than the other one. The Ti in TiO2/RH-MCM-41 was anatase titania with octahedral geometry located outside the mesoporous framework. This form was more an active
phase for the photodegradation and the reaction parameters on this catalyst were further investigated. The optimum catalyst
weight to methyl orange volume ratio was 5 g/L and the optimum initial concentration of the dye was 2.0 ppm. The degradation
rate obeyed pseudo-first order and the adsorption of methyl orange on TiO2/RH-MCM-41 obeyed Langmuir isotherm. 相似文献
9.
10.
N. V. Lebukhova V. S. Rudnev P. G. Chigrin K. S. Makarevich I. B. Lukiyanchuk N. F. Karpovich 《Catalysis in Industry》2011,3(3):294-300
Two methods were used to obtain a catalytically active oxide coating on the surface of titanium for the catalytic afterburning
of diesel soot: plasma electrochemical formation of an oxide film on the surface of titanium and extraction pyrolytic deposition
of the Li2Cu2(MoO4)3 compound. The Li2Cu2(MoO4)3/TiO2 + SiO2/Ti compositions synthesized by the single-step extraction pyrolytic treatment of the oxidized surface of titanium ensured
a high burning rate of soot of ∼300°C. The subsequent deposition of Li2Cu2(MoO4)3 lowers the activity of the catalyst, due probably to the growth of molybdate phase crystallites and the filling of open oxide
film pores. Double lithium-copper molybdate is able to reduce appreciably the concentration of CO in the oxidation products
of soot. The advantages of these methods are the possibility of forming high-cohesion durable coatings on surfaces of any
complexity, the simplicity of their implementation, and high productivity and low cost. The obtained results can be recommended
for use in developing methods for creating composite coatings on catalytic soot filters. 相似文献
11.
Thuy-Duong Nguyen-Phan Viet Hung Pham Hyunran Yun Eui Jung Kim Seung Hyun Hur Jin Suk Chung Eun Woo Shin 《Korean Journal of Chemical Engineering》2011,28(12):2236-2241
Thermally-reduced graphene oxide/TiO2 composites (TRGO/Ti) were prepared by the thermal reduction of graphene oxide/TiO2 composite that was obtained from a simple, environmentally friendly, one-step colloidal blending method. The changes in structural
and textural properties as well as their corresponding photocatalytic activities were investigated as a function of calcination
temperature. The presence of stacked TRGO sheets significantly retarded both the aggregation and the crystalline phase transformation
of TiO2 as increasing the temperature from 200 to 600 °C. TRGO/Ti composites exhibited higher photocatalytic activity for the degradation
of methylene blue in comparison with pure TiO2 due to the increase in specific surface area and the formation of π-π conjugations between dye compounds and aromatic regions of TRGO. However, increasing the calcination temperature resulted
in the lower photoactivity and slower kinetics, which can be ascribed to the decrease in surface area, the reduction of oxygen
vacancies, and the loss of functional groups at the edges or on the basal planes of the TRGO sheets. 相似文献
12.
Kang Shanjiao Dou Tao Li Qiang Duan Aijun Zheng Yanying Pan Huifang 《Journal of Porous Materials》2008,15(2):159-162
This paper presents the direct synthesis of super-low SiO2/Al2O3 ratio zeolite beta molecular sieve through a novel route, by which some of aluminium species are added during crystaling
process. The IR results show that with the increase of aluminium content in the framework, the frequency of the band in the
range of framework vibration (1060–1090 cm−1) shifts to the lower wave-number; the BET surface-area decreases and the basicity of zeolite becomes stronger. In a second
step, new adsorbents were obtained by solid-state ion exchanging zeolite beta with Cu(I), Ag(I) cations. The deep-desulfurization
(sulfur levels of <1 ppmw) tests were performed using fixed-bed adsorption technique, the sulfur content of the treated and
untreated gasoline was analyzed by microcoulometry. The experimental results show that the desulfurization performance of
sorbents decreases in order: Cu(I)beta > Ag(I)beta > Na-beta. The best sorbent, Cu(I)beta, has breakthrough adsorption capacities
of 0.236 mmolS/g of sorbent for model gasoline. 相似文献
13.
Ordered hexagonal mesoporous TiO2 thin film was prepared by the evaporation-induced self-assembly (EISA) method using triblock copolymer (Pluronic P123) and
tetrabutyl orthotitanate (Ti(OBu
n
)4, TBOT) in 1-methoxy-2-propanol (C4H10O2, PGME) solvent. The arrangement of mesopores was identified by small-angle X-ray diffraction and transmission electron microscopy
(TEM). The well-ordered hexagonal mesoporous TiO2 had a high specific surface area of 239 m2/g and an average pore size of 6.3 nm. The structure of mesoporous TiO2 thin film was anatase with a 5.1 nm crystallite. The absorption band shift of the mesoporous TiO2 toward longer wavelengths as calcined at 350 °C due to the residual carbon. 相似文献
14.
The approach to synthesize one-dimensional photonic SiO2–TiO2 crystals by sol–gel methods is developed. Using the method of transfer matrices, structures consisting of 13 layers of alternating materials having the properties of one-dimensional photonic crystals with the minimal transmission coefficient of 7% in the photonic band gap range and that of 97.5% in the remaining spectrum parts are calculated and experimentally created. The positions of the photonic band gaps change along with the thicknesses of the layers of the materials composing the photonic crystal. The possibility of creating an optical filter as a result of introducing a structural defect in the form of a layer of doubled thickness is demonstrated. 相似文献
15.
Jae-Hyoung Park Yong-Su Seo Hyun-Seung Kim Il-Kyu Kim 《Korean Journal of Chemical Engineering》2011,28(8):1693-1697
The photodegradation of BTEX (benzene, toluene, ethylbenzene and xylene) in a photocatalytic fluidized bed reactor with TiO2/SiO2 was investigated. The TiO2 film was prepared using the sol-gel method and coated onto silica-gel powder. The effects of the superficial gas velocity
and SiO2 size on the photodegradation of BTEX were examined in a fluidized bed reactor. At steady-state operation, above 79, 79, 99,
98, and 98% removal efficiencies were achieved for benzene, toluene, ethylbenzene, m, p-xylene and o-xylene, respectively,
under optimal conditions (2.0 U
mf
of superficial gas velocity and 1.43 of height/diameter ratio). The reaction product such as CO2 was detected and intermediate products such as benzaldehyde, malonic acid, acetaldehyde, and formic acid were identified
from the photocatalytic reaction. Also, small amounts of benzoic acid and benzyl alcohol were found through analyzing the
intermediate species adsorbed on the photocatalysts. The experimental results can lead to the development of an efficient
photocatalytic treatment system that utilizes solar energy and TiO2/SiO2 photocatalysts. 相似文献
16.
Mun-Seon Song Kalimuthu Vijayarangamuthu EunJi Han Ki-Joon Jeon Jeong-Won Seo 《Korean Journal of Chemical Engineering》2016,33(8):2392-2395
We demonstrate a facile modification of rutile TiO2 and its anti-bacterial activity under solar irradiation. The modification of rutile TiO2 was done by microwave-assisted hydrothermal process with hydrogen peroxide (H2O2) as a solvent. The structural properties were analyzed by using XRD and Raman studies. The modified rutile TiO2 shows no change either crystalline phase or crystalline size. The formation of Ti-OH was observed in Raman study. The TEM analysis shows modification on the surface of rutile TiO2. The photocatalytic disinfection of Escherichia coli (E. coli) under solar irradiation shows double-times better performance by modified rutile TiO2 compared to rutile TiO2. The enhancement of anti-bacterial activity was attributed surface modification and Ti-OH. 相似文献
17.
Philomena Schlexer Hsin-Yi Tiffany Chen Gianfranco Pacchioni 《Catalysis Letters》2017,147(8):1871-1881
18.
19.
Chockalingam Karunakaran Paramasivan Gomathisankar Govindasamy Manikandan 《Korean Journal of Chemical Engineering》2011,28(5):1214-1220
The photocatalytic efficiencies of TiO2 nanocrystals of different modifications (anatase, rutile, P25 Degussa, Hombikat), to oxidize cyanide ion and subsequently
the cyanate also, under natural sunlight at 950±25W m−2 in alkaline solution have been compared. The oxides have been characterized by powder XRD, UV-visible diffuse reflectance
and impedance spectroscopies. Under identical solar irradiance, the reaction follows Langmuir-Hinshelwood kinetics on cyanide,
and depends on the apparent area of the catalyst bed and dissolved oxygen. However, the adsorption of cyanide on TiO2 in dark is too small to be measured analytically. The photocatalytic activity of TiO2 is not solely governed by the band gap or charge-transfer resistance or capacitance or phase composition but is in accordance
with the specific surface area or the average crystallite size; rutile is an exception. 相似文献
20.
Kirk T. Kitchin Steve Stirdivant Brian L. Robinette Benjamin T. Castellon Xinhua Liang 《Particle and fibre toxicology》2017,14(1):50