scholarly journals Synthesis of Ag decorated TiO2 nanoneedles for photocatalytic degradation of methylene blue dye

Author(s):  
Noor J. Ridha ◽  
Firas K Alosfur ◽  
Hiba Basim Abbas Kadhim ◽  
Luma Majeed Ahmed

Abstract Water pollution due to the discharge of industrial effluents such as dyes is a serious concern that requires a potential remedy. In this context, photocatalysis is a potent and ecofriendly strategy to degrade these toxic water effluents. In this study, a novel approach to prepare TiO2 nanoneedles decorated with Ag nanoparticles is reported. The sample was prepared using modified photodeposition and was annealed at 400 °C. The X-ray diffraction (XRD) revealed that TiO2 in anatase phase with the presence of Ag were prepared successfully. The corresponding crystalline size of TiO2 and Ag were 6.86 nm and 3.94 nm, respectively. The scanning electron microscopy (SEM) showed that the prepared TiO2 exhibited nanoneedles structure decorated with Ag nanoparticles. The prepared sample exhibited impressive photocatalytic performance toward degrading of 50 ppm Methyl Blue (MB) in the presence of UV irradiation. Using catalyst dose of 4 mg the photodegradation efficiency (PDE) reached to 98.7% after 50 min of UV irradiation. This improved photocatalytic activity is attributed to high catalytic activity and surface area of the synthesized Ag decorated TiO2 nanoneedles.

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Jun Yao ◽  
Chaoxia Wang

TiO2sol was prepared for the degradation of methylene blue (MB) solution under ultraviolet (UV) irradiation. The absorption spectra of MB indicated that the maximum wavelength, 663 nm, almost kept the same. The performance of 92.3% for color removal was reached after 160 min. The particle size ofTiO2sol was about 22.5 nm. X-ray diffraction showed thatTiO2consisted of a single anatase phase. The small size and anatase phase probably resulted in high photocatalytic activity ofTiO2sol. The degradation ratio decreased as the initial concentration of MB increased. The photodegradation efficiency decreased in the order ofpH 2>pH 9>pH 7. Regarding catalyst load, the degradation increased with the mass of catalyst up to an amount of 1.5 g⋅L−1then decreased as the mass continued to increase. The addition ofH2O2toTiO2sol resulted in an increase on the degradation ratio.


2019 ◽  
Vol 8 (2) ◽  
pp. 94-102
Author(s):  
Ghizlane Erradi ◽  
Farida El yousfi ◽  
Mostafa Stitou

Removal of industrial waste becomes increasingly critical for environmental protection. This study aims to search for effective and less expensive adsorbents in order to remove methylene blue (MB) commonly used in many industrial sectors. To this end, we experiment Helix aspersa snail shell as a biosorbent for the removal of MB. The raw snail shells were cleaned, smashed, and characterized afterwards using a scanning electron microscopy (SEM) coupled with an energy dispersive X-Ray analysis (EDX) and by X-ray diffraction. Different parameters were tested in order to identify the optimal conditions for the effective removal of MB. Our experimental results showed that, within the first ten minutes, a remarkable elimination of methylene blue dye reaching a percentage of 82%, with the following optimal conditions; 3.5 g of the adsorbent, initial MB concentration of 20 mg/L, the temperature of 15 °C, and agitation of 250 rpm. This study showed that the use of snail shell waste has inevitably a positive impact on the protection of the environment, in particular, the purification of industrial effluents.


2019 ◽  
Vol 8 (2) ◽  
pp. 94
Author(s):  
Ghizlane Erradi ◽  
Farida El yousfi ◽  
Mostafa Stitou

<p>Removal of industrial waste becomes increasingly critical for environmental protection. This study aims to search for effective and less expensive adsorbents in order to remove methylene blue (MB) commonly used in many industrial sectors. To this end, we experiment <em>Helix aspersa</em> snail shell as a biosorbent for the removal of MB. The raw snail shells were cleaned, smashed, and characterized afterwards using a scanning electron microscopy (SEM) coupled with an energy dispersive X-Ray analysis (EDX) and by X-ray diffraction. Different parameters were tested in order to identify the optimal conditions for the effective removal of MB. Our experimental results showed that, within the first ten minutes, a remarkable elimination of methylene blue dye reaching a percentage of 82%, with the following optimal conditions; 3.5 g of the adsorbent, initial MB concentration of 20 mg/L, the temperature of 15 °C, and agitation of 250 rpm. This study showed that the use of snail shell waste has inevitably a positive impact on the protection of the environment, in particular, the purification of industrial effluents.</p>


2018 ◽  
Vol 7 (2) ◽  
pp. 88-97
Author(s):  
Abderhamane Boutelala ◽  
Fouzia Bourfaa ◽  
Mohamed Mahtali

Titanium oxide (TiO2) is one of the most important semiconductors because of their properties. This study was carried out to investigate the influence of the number of layers of Co -doped TiO2 thin films obtained by sol–gel method on the photocatalytic activity. The crystalline structure of films is characterised by means of X-ray diffraction and Raman spectroscopy. All the films were of anatase phase and the particle size was in nanoscale. The surface morphology was studied by atomic force microscopy. The optical properties were investigated by UV-visible spectroscopy. The photocatalytic properties of the samples were tested on the degradation of methylene blue dye solution. The results indicated that photocatalysis is more important when the number of dipping of films increases.Keywords: Photocatalysis, X-ray diffraction, TiO2, thin films, methylene blue.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeasmin Akter ◽  
Md. Abu Hanif ◽  
Md. Akherul Islam ◽  
Kamal Prasad Sapkota ◽  
Jae Ryang Hahn

AbstractA convenient route was developed for the selective preparation of two stable nanocomposites, Ti3+/TiO2/CNT (labeled as TTOC-1 and TTOC-3) and Ti3+/TiO2/carbon layer (labeled as TTOC-2), from the same precursor by varying the amount of single-walled carbon nanotubes used in the synthesis. TiO2 is an effective photocatalyst; however, its wide bandgap limits its usefulness to the UV region. As a solution to this problem, our prepared nanocomposites exhibit a small bandgap and wide visible-light (VL) absorption because of the introduction of carbonaceous species and Ti3+ vacancies. The photocatalytic efficiency of the nanocomposites was examined via the degradation of methylene blue dye under VL. Excellent photocatalytic activity of 83%, 98%, and 93% was observed for TTOC-1, TTOC-2, and TTOC-3 nanocomposites within 25 min. In addition, the photocatalytic degradation efficiency of TTOC-2 toward methyl orange, phenol, rhodamine B, and congo red was 28%, 69%, 71%, and 91%, respectively, under similar experimental conditions after 25 min. Higher reusability and structural integrity of the as-synthesized photocatalyst were confirmed within five consecutive runs by photocatalytic test and X-ray diffraction analysis, respectively. The resulting nanocomposites provide new insights into the development of VL-active and stable photocatalysts with high efficiencies.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Durga Sankar Vavilapalli ◽  
Ambrose A. Melvin ◽  
F. Bellarmine ◽  
Ramanjaneyulu Mannam ◽  
Srihari Velaga ◽  
...  

AbstractIdeal sillenite type Bi12FeO20 (BFO) micron sized single crystals have been successfully grown via inexpensive hydrothermal method. The refined single crystal X-ray diffraction data reveals cubic Bi12FeO20 structure with single crystal parameters. Occurrence of rare Fe4+ state is identified via X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The lattice parameter (a) and corresponding molar volume (Vm) of Bi12FeO20 have been measured in the temperature range of 30–700 °C by the X-ray diffraction method. The thermal expansion coefficient (α) 3.93 × 10–5 K−1 was calculated from the measured values of the parameters. Electronic structure and density of states are investigated by first principle calculations. Photoelectrochemical measurements on single crystals with bandgap of 2 eV reveal significant photo response. The photoactivity of as grown crystals were further investigated by degrading organic effluents such as Methylene blue (MB) and Congo red (CR) under natural sunlight. BFO showed photodegradation efficiency about 74.23% and 32.10% for degrading MB and CR respectively. Interesting morphology and microstructure of pointed spearhead like BFO crystals provide a new insight in designing and synthesizing multifunctional single crystals.


2003 ◽  
Vol 21 (5) ◽  
pp. 451-462 ◽  
Author(s):  
Sameer Al-Asheh ◽  
Fawzi Banat ◽  
Leena Abu-Aitah

An improvement in the adsorption capacity of naturally available bentonite towards water pollutants such as Methylene Blue dye (MBD) is certainly needed. For this purpose, sodium bentonite was activated by two methods: (1) treatment with sodium dodecyl sulphate (SDS) as an ionic surfactant and (2) thermal treatment in an oven operated at 850°C. Batch adsorption tests were carried out on removing MBD from aqueous solution using the above-mentioned bentonites. It was found that the effectiveness of bentonites towards MBD removal was in the following order: thermal-bentonite > SDS-bentonite > natural bentonite. X-Ray diffraction analysis showed that an increase in the microscopic bentonite platelets on treatment with SDS was the reason behind the higher uptake of MBD. An increase in sorbent concentration or initial pH value of the solutions resulted in a greater removal of MBD from the solution. An increase in temperature led to an increase in MBD uptake by the bentonites studied in this work. The Freundlich isotherm model was employed and found to represent the experimental data well.


2012 ◽  
Vol 730-732 ◽  
pp. 925-930
Author(s):  
Daniela Nunes ◽  
Vanessa Livramento ◽  
Horácio Fernandes ◽  
Carlos Silva ◽  
Nobumitsu Shohoji ◽  
...  

Nanostructured copper-diamond composites can be tailored for thermal management applications at high temperature. A novel approach based on multiscale diamond dispersions is proposed for the production of this type of materials: a Cu-nDiamond composite produced by high-energy milling is used as a nanostructured matrix for further dispersion of micrometer sized diamond. The former offers strength and microstructural thermal stability while the latter provides high thermal conductivity. A series of Cu-nDiamond mixtures have been milled to define the minimum nanodiamond fraction suitable for matrix refinement and thermal stabilization. A refined matrix with homogenously dispersed nanoparticles could be obtained with 4 at.% nanodiamond for posterior mixture with mDiamond and subsequent consolidation. In order to define optimal processing parameters, consolidation by hot extrusion has been carried out for a Cu-nDiamond composite and, in parallel, for a mixture of pure copper and mDiamond. The materials produced were characterized by X-ray diffraction, scanning and transmission electron microscopy and microhardness measurements.


Sign in / Sign up

Export Citation Format

Share Document