Nanostructured Zn-Ti layered double hydroxides with reduced photocatalytic activity for sunscreen application

2019 ◽  
Vol 21 (3) ◽  
Author(s):  
Orielia Pria Egambaram ◽  
Sreejarani Kesavan Pillai ◽  
Marlize Lategan ◽  
Suprakas Sinha Ray
Keyword(s):  
Photocatalytic Activity ◽  
Layered Double Hydroxides ◽  
Double Hydroxides

Nanocomposite Photocatalyst Based on Layered Double Hydroxides (LDHs) Associated with TiO2

2014 ◽  
Vol 92 ◽  
pp. 100-109 ◽  
Author(s):  
Jonjaua Ranogajec ◽  
Andrijana Sever-Skapin ◽  
Ognjen Rudic ◽  
Snezana Vucetic
Keyword(s):  
Photocatalytic Activity ◽  
Layered Double Hydroxides ◽  
Direct Contact ◽  
Building Materials ◽  
Specific Problem ◽  
The Self ◽  
Different Types ◽  
Double Hydroxides ◽  
Positive Effect ◽  
Material Porosity

The surfaces of building materials are constantly exposed to the actions of environmental factors, pollutants of inorganic and organic origin as well as to microorganisms, which significantly contribute to corrosion phenomena.The application of coatings decreases the negative action of the pollutants minimizing their direct contact with the substrate. Different types of coatings with additional functions have been developed. A specific problem of these applications is the lack of compatibility of the photocatalysts with the surface of the building materials and the detachment of potentially toxic TiO2nanoparticles. In the present study, this problem was solved by the proper immobilization of TiO2nanoparticles onto the photocatalyst support, layered double hydroxides (LDHs). The newly formed coating possesses acceptable porosity for a porous building material (porosity within the range of 30-46 %) and satisfied photocatalytic activity, as well as mineralogical compatibility with the substrates (mortars, renders, bricks). Additionally, a positive effect considering the self-cleaning phenomenon was attained.

scholarly journals High efficient photocatalytic activity of Zn-Al-Ti layered double hydroxides nanocomposite

2018 ◽  
Vol 149 ◽  
pp. 01087 ◽  
Author(s):  
F. Amor ◽  
A. Diouri ◽  
I. Ellouzi ◽  
F. Ouanji ◽  
M. Kacimi
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Uv Irradiation ◽  
Layered Double Hydroxides ◽  
Removal Rate ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
High Efficient ◽  
Double Hydroxides

This work establishes a simple method for synthesising layered double hydroxides (LDHs) powders with coprecipitation. The characteristics of the samples were investigated y X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectrophotometer UV–Vis (DRS). Non-uniform distribution was shown for LDHs samples by SEM. Photocatalytic efficiencies were tested using methylene blue (MB) dye as a model contaminant under UV irradiation. In particular, Zn–Al-Ti LDH exhibited an excellent performance towards MB degradation compared with commercial TiO2 nanoparticles. Methylene blue removal percentage was reached at almost 100%, whereas commercial TiO2 reached a removal rate of only 66% under the same conditions within 20 min. The aim of the current work is to prepare Zn-Al-Ti layered double hydroxides nanocomposite and to evaluate their photocatalytic activity in the removal of methylene blue under UV irradiation.

Photocatalytic decolourization of methylene blue using [Zn-Al] layered double hydroxides synthesized at different molar cationic ratios

Clay Minerals ◽  
2017 ◽  
Vol 52 (2) ◽  
pp. 203-215 ◽  
Author(s):  
Kaouther Abderrazek ◽  
Najoua Frini Srasra ◽  
Ezzeddine Srasra
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Layered Double Hydroxides ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled ◽  
Molar Ratios ◽  
Constant Ph ◽  
Double Hydroxides

Abstract[Zn-Al] layered double hydroxides (LDH) with cationic molar ratios of R = Zn/Al 1–5 were synthesized by the coprecipitation method at constant pH = 10. The samples synthesized and their derived forms obtained after calcination at 500°C and at 900°C (denoted Zn-Al-R, Zn-Al-R-500 and Zn-Al-R-900, respectively), were characterized by X-ray diffraction (XRD), inductively coupled plasmamass spectrometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance spectroscopy and nitrogen physisorption at −196°C. The XRD study showed: (1) the presence of accessory ZnO with the LDH in samples synthesized with R ≥ 3; and (2) the lamellar structure was destroyed at 500°C which made room for a poorly ordered ZnO phase, while calcination at 900°C yielded well crystallized ZnO and ZnAl2O4. The photocatalytic activity of the calcined and the unheated samples was evaluated for the decolourization of methylene blue. The photocatalytic activity was dependent on the cationic ratio R and on the calcination temperature. The sample Zn-Al-3 displayed maximum photocatalytic activity. Calcination at 500 and 900°C improved the photocatalytic activity of LDH synthesized at R = 1 and 2.

scholarly journals The influence of the UV irradiation intensity on photocatalytic activity of ZnAl layered double hydroxides and derived mixed oxides

2012 ◽  
Vol 18 (2) ◽  
pp. 295-303 ◽  
Author(s):  
Milica Hadnadjev-Kostic ◽  
Tatjana Vulic ◽  
Dmitar Zoric ◽  
Radmila Marinkovic-Neducin
Keyword(s):  
Photocatalytic Activity ◽  
Uv Irradiation ◽  
Layered Double Hydroxides ◽  
Mixed Oxide ◽  
Mixed Oxides ◽  
Uv Light ◽  
Light Irradiation ◽  
Irradiation Intensity ◽  
Uv Light Irradiation ◽  
Double Hydroxides

Layered double hydroxides (LDHs) have been studied to a great extent as environmental-friendly complex materials that can be used as photocatalysts or photocatalyst supports. ZnAl layered double hydroxides and their derived mixed oxides were chosen for the investigation of photocatalytic performances in correlation with the UV intensities measured in the South Pannonia region. Low supersaturation coprecipitation method was used for the ZnAl LDH synthesis. For the characterization of LDH and thermal treated samples powder X-ray diffraction (XRD), scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), nitrogen adsorption-desorption were used. The decomposition of azodye, methylene blue was chosen as photocatalytic test reaction. The study showed that the ZnAl mixed oxide obtained by thermal decomposition of ZnAl LDH has stable activity in the broader UV light irradiation range characterizing the selected region. Photocatalytic activity could be mainly attributed to the ZnO phase, detected both in LDH and thermally treated samples. The study showed that the ZnAl mixed oxide obtained by the calcination of ZnAl LDH has a stable activity within the measured UV light irradiation range; whereas the parent ZnAl LDH catalyst did not perform satisfactory when low UV irradiation intensity is implied.

scholarly journals Enhanced photocatalytic activity of TiO2-impregnated with MgZnAl mixed oxides obtained from layered double hydroxides for phenol degradation

2015 ◽  
Vol 357 ◽  
pp. 1765-1775 ◽  
Author(s):  
Marciano Fabiano de Almeida ◽  
Carlos Roberto Bellato ◽  
Ann Honor Mounteer ◽  
Sukarno Olavo Ferreira ◽  
Jaderson Lopes Milagres ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Layered Double Hydroxides ◽  
Mixed Oxides ◽  
Phenol Degradation ◽  
Double Hydroxides
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