Improvement of TiO2/LDPE Composite Films for Photocatalytic Oxidation of Acetone

2014 ◽  
Vol 931-932 ◽  
pp. 235-240 ◽  
Author(s):  
Kowit Suwannahong ◽  
Sanya Sirivithayapakorn ◽  
Pongsak Noophan ◽  
Wipada Sanongraj

Titanium dioxide with coupling agent (ETES) was applied as a photocatalyst for a synthesis of the TiO2/LDPE composite film. The physical properties of TiO2/LDPE composite film were analyzed by a Scanning Electron Microscope (SEM). TiO2 particles were impregnated into the polymer matrix film as a LDPE composite film. The results from the X-ray Diffraction (XRD) technique revealed that the structure of TiO2/LDPE composite film were anatase crystalline. The chemical structure of the TiO2/ LDPE composite films were analyzed by an ATR-Fourier transforms infrared (ATR-FTIR) spectrometer. Wavenumber of FTIR spectra at 719 cm1 indicated the Ti-O-Ti bond. Band gap energies of the films ranged from 3.19-3.29 eV. The photocatalytic activity of the film was tested for removal of gaseous acetone in a closed chamber. Experimental conditions were set as follows: a UV light intensity of approximately 2.7 mW.cm-2, flow rate of 2 L.min-1, and an initial acetone concentration of about 435±20 ppm. While the catalyst dosage was varied from 3% to 15% (wt. cat/wt. film).The degradation rate of acetone increased when increasing dosage of TiO2 from 3% to 10%, then decreased a little bit when increasing the dosage to 15%. The TiO2/LDPE composite film at the dosage of 10% yielded the highest removal efficiency of 75%, followed by the film at the dosage of 15%, 5%, and 3%, respectively.

1996 ◽  
Vol 458 ◽  
Author(s):  
S. Govindarajan ◽  
J. J. Moore ◽  
T. R. Ohno ◽  
J. Disam

ABSTRACTA novel coating architecture is being examined for enhancing the high temperature, oxidation resistance of molybdenum. The coating incorporates a thin, composite film of MoSi2+1.96 mole fraction SiC in order to match the coefficients of thermal expansion between the molybdenum substrate and the coating. Since the as-deposited composite film is amorphous in nature, a diffusion anneal treatment is carried out at 1000°C to achieve crystallization of the film. In this paper, a detailed examination of the Mo-MoSi2+1.96 SiC interface will be presented. The microstructural features of the composite films will be discussed based on electron microscopy, auger electron spectroscopy (AES), and X-ray diffraction analysis. Finally, a novel diffusion barrier layer for minimizing silicon and carbon diffusion from the coating to the substrate will be discussed.


2019 ◽  
Vol 26 (07) ◽  
pp. 1850215
Author(s):  
J. Z. LOU ◽  
Y. S. ZHANG ◽  
X. H. DAI ◽  
J. M. SONG ◽  
Z. N. LI ◽  
...  

Pt:MgO composite films are prepared on quartz substrates at room temperature by magnetron sputtering and pulsed laser co-deposition (MSPLC) method, in which the volume ratio of the composite film can be easily controlled by MSPLC method. The sample with Pt volume percents of 40%, 50%, 60% and 70% are prepared, and all the samples are further annealed at 800∘C for 30[Formula: see text]min. Impacts of Pt content on the structural and physical properties have been investigated. Pt (111), (002) and (220) peaks can be observed, and the peak intensity increases with the increase of Pt content, as can be seen from the X-ray diffraction (XRD) pattern. Scanning electron microscope (SEM) results show that the size and density of grains increase and the distance between grains is decreased with the volume fraction increase. Significant absorption peaks were observed for different volume percentage of Pt:MgO composite film. Absorption peaks can be observed at 200, 220, 250 and 275[Formula: see text]nm, corresponding to Pt volume percents of 40%, 50%, 60% and 70%, respectively. The observed red shift of the absorption peak can be mainly related to the increase of Pt grain sizes.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Lefu Mei ◽  
Ranfang Zuo ◽  
Jing Xie ◽  
Libing Liao ◽  
Hao Ding

TiO2-ZrO2composite film with the grain size of 50 nm was synthesized by electric field and heat (EF&H) treatments. Portions of O atoms in the TiO2network structure were replaced by N atoms as revealed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses, suggesting formation of a nonstoichiometric compoundTiO2-xNxon the composite film. The UV-Vis spectra of the film suggested that the visible light with wavelength of 550 nm could be absorbed for the N-doped composite film after EF&H treatment in comparison to a cutoff wavelength of 400 nm for the composite film without EF treatment. Photocatalytic experiments showed that the degradation rate of methylene blue by N-doped composite films increased significantly under visible light irradiation. The partial replacement of O by doped N played a very important role in narrowing the band gap and improving the visible light photocatalytic reactivity.


2017 ◽  
Vol 15 (7) ◽  
pp. 491-501
Author(s):  
Sunun KHAMI ◽  
Wipawee KHAMWICHIT ◽  
Ratthapol RANGKUPAN ◽  
Kowit SUWANNAHONG

In this paper, toluene removal via photocatalytic oxidation using TiO2 dip coated nanofilms is presented. Nanofilms were synthesized from bacterial cellulose using the electrospinning technique. The physical properties of the nanofilms were analyzed by scanning electron microscopy (SEM). The ratio of bacterial cellulose/nylon used in the spinning process was 0.165:1. The results from SEM showed that the structure of the TiO2 composite nanofilms was rutile crystalline with an average particle size of 20 nm, and synthesized nanofilms had an average size of 20 - 30 nm. The band gap energies of TiO2-dip coated nanofilms ranged from 3.18 - 3.21 eV. SEM results of TiO2 coated nanofilms suggested that the TiO2 was rather uniformly distributed onto the surface of the nanofilms. The actual amount of TiO2 coated on the nanofilms was estimated using thermogravimetric analysis (TGA) for 1x1 cm2 surface area. It was found that 0.1852, 0.2897 and 0.7275 mg of TiO2 were coated on the surface of the nanofilms for 1, 2.5 and 5 % (weight) TiO2 dosage, respectively. The photocatalytic activity of the nanofilms was tested for the removal of gaseous toluene in a photocatalytic reactor. Experimental conditions were set as follows: UV light intensity of approximately 2.7 mW.cm-2, flow rate of 0.2 L.min-1, and an initial toluene concentration of about 200±20 ppm, and a retention time at 200 min. The degradation rate of toluene increased with increasing dosage of TiO2 from 1, 2.5 and 5 %. The nanofilms at a 5 % dosage yielded the highest removal efficiency of 92.71 %, followed by the 2.5 and 1 % dosage, respectively.


2017 ◽  
Vol 10 (5) ◽  
pp. 257
Author(s):  
R. Crepaldi ◽  
G. M. Titato ◽  
F. M. Lanças ◽  
E. P. Sichieri ◽  
M. Telascrea ◽  
...  

Volatile Organic Compounds (VOCs) constitutes an important class of air pollutants, and benzene is one of the main contaminants of indoor air pollution. Among the methods for the treatment of environments with a high VOCs concentration is the photocatalytic oxidation by TiO2 (anatase) ceramic coated surfaces. The effectiveness of VOCs photodegradation studies using active ceramic tiles made in laboratory is well reported in the literature. However, this has not been reported using commercial tiles, although active ceramics are sold for such a function. In this context, this study proposed the assessment of commercial active ceramic tiles capacity in the photocatalytic degradation of benzene in indoor air. The development of this work arose from two questions: a) if the commercial active ceramic tiles are efficient in the VOCs degradation as the manufacturers claim; b) if they are able to degrade VOCs in indoor building environments. Experiments were conducted in laboratory’s scale, using an adapted simulation chamber. The volatilized benzene entered in contact with the commercial ceramic tile under fluorescent light and ultraviolet (UV) light of 365 nm. Samples of the chamber internal air were collected by adsorption on polydimethylsiloxane fibres in headspace technique (SPME-HS). The evaluation of the benzene degradation occurred by gas chromatography analysis with mass spectrometry (GC-MS). The characterization of commercial active ceramic samples occurred by techniques of X-Ray Diffraction Powder (XRD), and Scanning Electron Microscopy (SEM) with Energy Dispersive Spectrometry (EDS). Results showed that, under the experimental conditions, the commercial active ceramic tile was not capable of the benzene photocatalytic oxidation. The ceramic characterization detected very low quantity of TiO2 on ceramic samples, being this fact attributed as the main responsible for the ceramic photocatalytic inactiveness.


2021 ◽  
pp. 089270572110075
Author(s):  
Kajal Mishra ◽  
Shishir Sinha

The present work focuses on surface functionalization, characterization, biodegradability and barrier properties of MOSF as a practicable reinforcement in PVA matrix. Film-forming dispersions at different concentrations of alkali and acid treatments were casted at room temperature. The effect of surface modifications on the developed film’s compositional, physical, mechanical, biodegradability and barrier properties were analyzed. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) were used to describe the functional composition, formation and surface morphology of the film. The 5% acid treated film significantly increases the tensile strength (33.69 MPa) and flexural strength (56.612 MPa), which was close to the frequently used LDPE and HDPE package films. Composite films were moisture absorptive but simultaneously capable to maintain uniformity and composition upon modifications. Lower water vapor permeability (1.42 × 10−10gs−1 m−1 Pa−1), eminent biodegradability proved the suitability of composite film for various packaging applications.


2020 ◽  
Vol 24 (1) ◽  
Author(s):  
Nguyen Dinh Lam

The Zn1-xAlxO nanorod (NR) were grown on ITO substrates by a hydrothermal process. The influences of the Al doping concentration on the surface morphology, structural, optical, and electrical characteristics of the Zn1-xAlxO NR/ITO composite film were investigated in detail. The results indicated that characteristics of the Zn1-xAlxO NR/ITO composite film were strongly influenced by the Al doping concentration. Furthermore, the lowest vertical resistance of the Zn1-xAlxO NR can be obtained when x = 0.01 and it strongly reduces when the concentration of UV light illumination increases. This reduction follows an exponential decay with a decay rate of 4.35. This result shows good photoconductivity response of the Zn1-xAlxO NR/ITO composite film and its ability to apply for optoelectronic devices material.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1457
Author(s):  
Fahad A. Alharthi ◽  
Abdulaziz Ali Alghamdi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad

In this study, we report the fabrication of graphitic carbon nitride doped zinc oxide nanocomposites, g-C3N4/ZnO, (Zn-Us) by using different amount of urea. They were further characterized by X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman, UV-vis, Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM) techniques. The prepared nanocomposites were used as photocatalysts for the mineralization of the light sensitive dyes Methylene Blue (MB) and Rose Bengal (RB) under UV light irradiation, and corresponding photo-mechanism was proposed. Benefiting from these photocatalytic characteristics, urea derived g-C3N4/ZnO photocatalysts have been found to have excellent photodegradation activity against the MB and RB for 6 h and 4 h, respectively. Under the given experimental conditions, the degradation percentage of fabricated Zn-Us were shown ~90% for both model dyes. Compared to cationic MB dye, anionic RB dye is more actively degraded on the surface of prepared photocatalysts. The results obtained can be effectively used for future practical applications in wastewater treatment


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1589 ◽  
Author(s):  
Xinxin Liu ◽  
Xiaofeng Chen ◽  
Junli Ren ◽  
Chunhui Zhang

In order to improve the strength of polyvinyl alcohol (PVA)/xylan composite films and endow them with ultraviolet (UV) shielding ability, TiO2-KH550 nanoparticles was synthesized and added into the PVA/xylan matrix. The TiO2-KH550 nanoparticle dispersed well in the 0.04% sodium hexametaphosphate (SHMP) solution under ultrasonic and stirring treatments. Investigations on the properties of the films showed that TiO2-KH550 had the positive impact on improving the strength, moisture, and oxygen barrier properties of the composite films. The maximum tensile strength (27.3 MPa), the minimum water vapor permeability (2.75 × 10−11 g·m−1·s−1·Pa−1), and oxygen permeability (4.013 cm3·m−2·24 h−1·0.1MPa−1) were obtained under the addition of 1.5% TiO2-KH550. The tensile strength of TiO2-KH550 reinforced composite film was increased by 70% than that of the pure PVA/xylan composite film, and the water vapor and oxygen permeability were decreased by 31% and 41%, respectively. Moreover, the UV transmittance of the film at the wavelength of 400 nm was almost zero when adding ≈1.5~2.5% (weight ratio, based on the total weight of PVA and xylan) of TiO2-KH550, which indicated the PVA/xylan composite films were endowed with an excellent UV light shielding ability.


Fibers ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 57 ◽  
Author(s):  
Rohan S. Dassanayake ◽  
Poorna T. Wansapura ◽  
Phat Tran ◽  
Abdul Hamood ◽  
Noureddine Abidi

A cellulose-cadmium (Cd)-tellurium (TE) quantum dots (QDs) composite film was successfully synthesized by incorporating CdTe QDs onto a cellulose matrix derived from waste cotton linters. Cellulose-CdTe QDs composite film was characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The antibacterial activity of the prepared composite film was investigated using the multidrug-resistance (MTR) Staphylococcus aureus bacteria. In vitro antibacterial assays demonstrated that CdTe QDs composite film can efficiently inhibit biofilm formation. Our results showed that the cellulose-CdTe QDs composite film is a promising candidate for biomedical applications including wound dressing, medical instruments, burn treatments, implants, and other biotechnology fields.


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