Photodecontamination of Vat Green 1 and Dianix Blue dyes by MWCNTs/x%TiO2 nanocomposites synthesized using evaporation method (original) (raw)
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International Journal for Research in Applied Science and Engineering Technology
Multi-walled carbon nanotubes/titanium dioxide nanocomposites MWCNTs/x%TiO 2 with different weight ratios of TiO 2 (x = 3, 6 and 10%) have been synthesized using a simple modified evaporation method. The structure of the synthesized nanocomposite photocatalysts were characterized using XRD, SEM, N 2 adsorption-desorption and diffused reflectance UV-Vis spectroscopic techniques. The photocatalytic activity of the synthesized photocatalysts toward decontamination of two local textile dyes (Dianix Blue and Vat Green 1 Dyes) as an industrial organic pollutants commonly used in dyeing factories in Egypt. Moreover, the suggested possible mechanism of the photodegradation processes was studied. Also optical band gap was estimated by Kubelka-Munk equation for MWCNTs and MWCNTs/x%TiO 2 (x = 3, 6 and 10%) giving rises values 3.51, 2.89, 2.80, 2.69 eV respectively. The photodegradation of the two textile dyes after complete degradation were measured using chemical oxygen demand processes.
Jurnal Rekayasa Kimia & Lingkungan, 2021
Synthetic dyes waste from textile industries, produce of the problematic pollutants in wastewater. TiO2 based photocatalysis are materials that exhibit excellent absorption behavior for organic compounds in wastewater due it properties including nontoxicity, high photocatalysis degradation ability, and chemical stabilities. However, several challenges exist regarding TiO2 nanotubes pure applications for dyes degradation such as poor affinity, high band gap energy, and difficulty of recovery and easy to recombination so it would decrease effectiveness of the photocatalysis process. Therefore, more design and optimization testing need to be conducted on the treatment conditions in order to reach higher removal efficiencies with lower costs. The modified physical properties by adding metal dopant, nonmetal, and sensitizer significantly enhanced photocatalysis activity. These parameters, which affect photocatalysis activity on degrade dyes waste pollutants, are discussed in the current ...
An Overview: Recent Development of Titanium Oxide Nanotubes as Photocatalyst for Dye Degradation
International Journal of Photoenergy, 2014
Today, organic dyes are one of the largest groups of pollutants release into environment especially from textile industry. It is highly toxic and hazardous to the living organism; thus, the removal of these dyes prior to discharge into the environment is essential. Varieties of techniques have been employed to degrade organic dyes and heterogeneous photocatalysis involving titanium dioxide (TiO2) appears to be the most promising technology. In recent years, TiO2nanotubes have attracted much attention due to their high surface area and extraordinary characteristics. This paper presents a critical review of recent achievements in the modification of TiO2nanotubes for dye degradation. The photocatalytic activity on dye degradation can be further enhanced by doping with cationic or anionic dopant.
Industrial & Engineering Chemistry Research, 2009
The photocatalytic degradation of a model textile dye, methyl orange (MO), using anodized titanium dioxide (TiO 2) nanotubes has been investigated. The effects of light intensity, dye concentration, external bias, pH, and nanotube dimensions (length, diameter, and wall thickness) on MO photodegradation have been examined. The application of a minimal bias of +0.0 versus saturated calomel electrode (SCE) can enhance the dye degradation at least 10 times compared to unbiased conditions for dye concentrations between 20 and 100 µM. The overall initial dye degradation rate demonstrates three types of dependence on dye concentration over a range from 2.5-100 µM. For lower dye concentrations (2.5-40 µM) and natural pH (∼6.0) conditions, Langmuir-Hinshelwood (LH) kinetics was observed. The nanotubes diameter, calcination condition, and the anatase-to-rutile ratio in the crystalline TiO 2 nanotubes together influence the photocatalytic and photoelectrochemical properties of the TiO 2 nanotubes.
Nanomaterials
In this study, titanium dioxide powder obtained by the sol-gel method and TiO2 nanotubes, were prepared. In order to increase the TiO2 photoactivity, the powders and nanotubes obtained were modified by dye sensitization treatment during the oxide synthesis. The sensitizers applied were Quinizarin (Q) and Zinc protoporphyrin (P). The materials synthesized were extensively characterized and it was found that the dye sensitization treatment leads to modify the optical and surface properties of Titania. It was also found that the effectiveness of the dye-sensitized catalysts in the phenol and methyl orange (MO) photodegradation strongly depends on the dye sensitizer employed. Thus, the highest degradation rate for MO was obtained over the conventional Q-TiO2 photocatalyst. In the case of the nanotubes series, the most effective photocatalyst in the MO degradation was based on TiO2-nanotubes sensitized with the dye protoporfirin (ZnP). Selected catalysts were also tested in the phenol an...
2012
This work is devoted to synthesize different semiconductor nanoparticles and their metal-hybrid nanocomposites such as TiO 2 , Au/TiO 2 , ZnO, and Au/ZnO. The morphology and crystal structure of the prepared nanomaterials are characterized by the TEM and XRD, respectively. These materials are used as catalysts for the photodegradation of Malathion which is one of the most commonly used pesticides in the developing countries. The degradation of 10 ppm Malathion under ultraviolet (UV) and visible light in the presence of the different synthesized nanocomposites was analyzed with high-performance liquid chromatography (HPLC) and UV-Visible Spectra. A comprehensive study is carried out for the catalytic efficiency of the prepared nanoparticles. Different factors influencing the catalytic photodegradation are investigated, as different light source, surface coverage, and nature of the organic contaminants. The results indicate that hybrid nanocomposite of the semiconductor-metal hybrid serves as a better catalytic system compared with semiconductor nanoparticles themselves.
The Journal of Physical Chemistry C, 2010
A carbon nanotubes (CNT)/TiO 2 nanocomposite photocatalyst has been prepared by a simple impregnation method, which is used, for the first time, for gas-phase degradation of benzene. It is found that the asprepared CNT/TiO 2 nanocomposite exhibits an enhanced photocatalytic activity for benzene degradation, as compared with that over commerical titania (Degussa P25). A similar phenomenon has also been found for liquid-phase degradation of methyl orange. The characterization of photocatalysts by a series of joint techniques, including X-ray diffraction, transmission electron microscopy, ultraviolet/visible (UV/vis) diffuse reflectance spectra, and photoluminescence spectra, discloses that CNT has two kinds of crucial roles in enhancement of photocatalytic activity of TiO 2. One is to act as an electron reservoir, which helps to trap electrons emitted from TiO 2 particles due to irradiation by UV light, therefore hindering electron-hole pairs recombination. The other is to act as a dispersing template or support to control the morphology of TiO 2 particles in the CNT/TiO 2 nanocomposite, and this important role was neglected in previous studies. Accordingly, a reasonable model is proposed to expain the role of CNT in CNT/TiO 2 composites as a photocatalyst for degradation of organic pollutants.
Visible light photocatalytic activity of MWCNT/TiO2 using the degradation of methylene blue
2019
Multi-walled carbon nanotubes (MWCNT)-doped TiO2 thin films were synthesized by the dip-coating method. The obtained products were characterized by SEM, EDX, XRD, and UV-vis absorption spectroscopy. The XRD patterns showed the presence of anatase phase. Absorption spectrum of MWCNT-doped TiO2 revealed a red shift in the optical absorption edge due to carbon doping. The photocatalytic properties were investigated using methylene blue (MB) degradation under visible light (400-700 nm). MWCNT/TiO2 thin films exhibited significantly higher photocatalytic activity as compared to undoped TiO2 thin films due to reduction of the rate of electron-hole recombination by doping carbon. Photocatalytic activity studies with different light source (white light and blue light) indicated a significantenhancement in photocatalytic removal under white light irradiation.
Journal of Colloid and Interface Science, 2014
The present manuscript focus on the synthesis of surface hydroxyl group enriched titanium dioxide nanotube (TNT) by hydrothermal method for preferential adsorption of methylene blue (MB) dye. The mixture of methylene blue (MB) and rhodamine B (RhB) dye was used to study the preferential adsorption nature of TNT. The synthesized TNT were characterized by various techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption, and ammonia-temperature programmed desorption (NH 3 -TPD) analysis. Result demonstrated that enhancement in the surface area of TNT and higher number of hydroxyl group on the surface of TNT. In the binary mixture, the adsorption of MB dye was 12.9 times higher as compared to RhB dye, which clearly indicated the preferential adsorption of MB dye on TNT surface. The preferential interaction of MB on TNT is due to the electrostatic interaction between the cationic MB and negatively charged TNT surface. The preferential adsorption of MB dye was studied by applying Langmuir, Freundlich and Sips isotherm; pseudo-first and second-order kinetic model. Furthermore, the regeneration of dye adsorbed TNT was carried out by eco-friendly photocatalytic process under the irradiation of ultraviolet light.