Effective optical nanoparticles and nanocomposites based on a carbon nanotubes-organic—inorganic nanohybrid for industrial pollutant removal

2020 ◽  
Vol 10 (6) ◽  
pp. 856-865
Author(s):  
Adil Alshoaibi
Keyword(s):  
Carbon Nanotubes ◽  
Zinc Oxide ◽  
Fatty Acid ◽  
Uv Light ◽  
Thermal Analyses ◽  
Interlayer Spacing ◽  
Band Gap Energy ◽  
Pollutant Removal ◽  
Photocatalytic Reactions ◽  
Zinc Aluminum Oxide

Improving the optical properties of zinc oxide to meet the practical requirements of photocatalytic reactions and solar cells is an ongoing challenge. To address this challenge, different nanostructures of ZnO were prepared from an organic—inorganic-CNTs nanohybrid. The nanohybrid was formed through intercalation of the long chain fatty acid C17H35COOH and carbon nanotubes into Zn–Al nanolayered structures. X-ray diffraction revealed an increase in the interlayer spacing of the Zn–Al layered double hydroxides from 0.75 nm to 2.1 nm after admixing with the CNTs and organic fatty acid. Thermal analyses and FTIR confirmed the formation of the CNTs–C18–Zn–Al nanohybrid. Three different thermal treatments were used to transform the nanohybrid into nanostructures of doped zinc oxide nanoparticles and zinc aluminum oxide nanocomposites. As a result of changes in the nano size and structure, the band gap energy of the products decreased from 3.3 eV to 1.8 eV, to give efficient photocatalysts. The nanomaterials were used to purify water through the photocatalytic degradation of colored pollutants under UV light. A kinetic study showed that water purification was achieved within a short time, demonstrating the effectiveness of the nanomaterials. The nanohybrid and its derivatives are attractive materials for designing-efficient photocatalysts for pollutant degradation.

scholarly journals Improving the Performance of Zinc Oxide Photocatalysts for Phenol Degradation through Addition of Lanthanum Species

2020 ◽  
Vol 23 (4) ◽  
pp. 109-116
Author(s):  
Wynona Agatha Nimpoeno ◽  
Hendrik Oktendy Lintang ◽  
Leny Yuliati
Keyword(s):  
Zinc Oxide ◽  
Photocatalytic Activity ◽  
Uv Light ◽  
Phenol Degradation ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Band Gap Energy ◽  
Fluorescence Emission Spectra ◽  
Green Approach ◽  
La Addition

One green approach to degrade organic pollutants, such as phenol, is through the photocatalytic reaction. Despite having large band gap energy, which is enough for phenol degradation, zinc oxide (ZnO) has low photocatalytic efficiency. In this study, ZnO was modified by lanthanum (La) species, and the improved photocatalytic activity was confirmed for degradation of phenol under visible and ultraviolet (UV) light irradiation. The ZnO and its modified photocatalysts were prepared by the hydrothermal method in the absence and presence of La species (0.01‒2 wt%). X-ray diffraction (XRD) patterns showed that the addition of La did not disturb the structure of ZnO, but slightly decreased the crystallite size. While the La addition up to 1 wt% did not affect the optical properties of the ZnO, the addition of 2 wt% La slightly red-shifted the absorption band edge of the ZnO. The Fourier-transform infrared (FT-IR) spectra showed La oxide formation observed at 515-540 cm-1 after 2 wt% La addition. Fluorescence emission spectra revealed that synthesized ZnO has oxygen vacancies at 558 nm, and the presence of 1 wt% La did not significantly affect the emission intensity. The photocatalytic activity of ZnO was influenced by the La addition, where the best performance was obtained on the ZnO with 1 wt% La. This study demonstrated that the optimum amount of La species could increase the performance of the ZnO.

Applications of ZnO and MgO Nanoparticles in Reducing Zinc Pollution Level in Rubber Manufacturing Processes: A Review

2020 ◽  
Vol 6 (2) ◽  
pp. 103-107 ◽  
Author(s):  
Seyyed Mohammad Javadi
Keyword(s):  
Zinc Oxide ◽  
Fatty Acid ◽  
Magnesium Oxide ◽  
Environmental Effects ◽  
Pollution Level ◽  
Oxide Nanoparticles ◽  
Mgo Nanoparticles ◽  
Magnesium Oxide Nanoparticles ◽  
Council Directive ◽  
Zno Particles

Background: Rubber vulcanization is a consolidated chemical process to enhance the mechanical properties of the polymeric material by sulfur crosslinking of the polymer chains, such as rubber. Vulcanization Activators are important rubber processing additives that activate sulfur cure and improve the efficiency of sulfur-based cure systems. The most common activator is zinc fatty acid ester that is often formed in-situ by the reaction of fatty acid with zinc oxide. Although zinc is one of the less harmful heavy metals, according to European Council Directive 2004/73/EC, the reduction of zinc level in the environment has become an important task because of its toxic effect on aquatic organisms. : The current study reviews the research achievements in the field of reducing the consumption of micronutrients of ZnO particles based on the use of nanoparticles instead of them in the polymer industry. Among the proposed methods, due to the less environmental effects of magnesium oxide, the use of MgO nanoparticles instead of zinc oxide has also achieved good results. Objective: The aim of this paper is considering suggested different methods on the reduction of using ZnO particles in related industries, the use of ZnO nanoparticles has had better results than its particles. In addition, due to the less environmental effects of magnesium oxide, magnesium oxide nanoparticles can be used instead of micronutrients of zinc oxide. Overall, the results of various investigations show that reducing the diameter of the zinc oxide particles reduces the amount required for curing the rubber and thus reduces its toxic effects. Also, the use of magnesium oxide nanoparticles instead of zinc oxide in different concentrations is investigated.

scholarly journals Deposition of Zinc Oxide Coatings on Wood Surfaces Using the Solution Precursor Plasma Spraying Process

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 183
Author(s):  
Ghiath Jnido ◽  
Gisela Ohms ◽  
Wolfgang Viöl
Keyword(s):  
Zinc Oxide ◽  
Ftir Spectroscopy ◽  
Photoelectron Spectroscopy ◽  
Color Change ◽  
Uv Light ◽  
Beech Wood ◽  
Nitrate Solution ◽  
Ftir Spectra ◽  
Solution Precursor ◽  
Wood Surfaces

In the present work, the solution precursor plasma spray (SPPS) process was used to deposit zinc oxide (ZnO) coatings on wood surfaces using zinc nitrate solution as precursor to improve the hydrophobicity and the color stability of European beech wood under exposure to ultraviolet (UV) light. The surface morphology and topography of the wood samples and the coatings were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The formation of ZnO was detected with the help of X-ray photoelectron spectroscopy (XPS) and by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectra of the coated samples showed the typical Zn–O band at 445 cm−1. According to the XPS analysis, the coatings consist of two different Zn-containing species: ZnO and Zn(OH)2. Variation of the deposition parameters showed that the most significant parameters affecting the microstructure of the coating were the solution concentration, the deposition scan speed, and carrier gas flow rate. The wettability behaviors of the coated wood were evaluated by measuring the water contact angle (WCA). The coatings that completely covered the wood substrates showed hydrophobic behaviors. UV-protection of wood surfaces after an artificial UV light irradiation was evaluated by color measurements and FTIR spectroscopy. The ZnO-coated wood surfaces were more resistant to color change during UV radiation exposure. The total color change decreased up to 60%. Additionally, the FTIR spectra showed that the wood surfaces coated with ZnO had more stability. The carbonyl groups formation and C=C-bonds consumption were significantly lower.

scholarly journals Complex Geometry Strain Sensors Based on 3D Printed Nanocomposites: Spring, Three-Column Device and Footstep-Sensing Platform

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1106
Author(s):  
Alejandro Cortés ◽  
Xoan F. Sánchez-Romate ◽  
Alberto Jiménez-Suárez ◽  
Mónica Campo ◽  
Ali Esmaeili ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
3D Printing ◽  
Complex Geometry ◽  
Uv Light ◽  
Shielding Effect ◽  
Strain Sensitivity ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Sensing Platform ◽  
Electromechanical Performance

Electromechanical sensing devices, based on resins doped with carbon nanotubes, were developed by digital light processing (DLP) 3D printing technology in order to increase design freedom and identify new future and innovative applications. The analysis of electromechanical properties was carried out on specific sensors manufactured by DLP 3D printing technology with complex geometries: a spring, a three-column device and a footstep-sensing platform based on the three-column device. All of them show a great sensitivity of the measured electrical resistance to the applied load and high cyclic reproducibility, demonstrating their versatility and applicability to be implemented in numerous items in our daily lives or in industrial devices. Different types of carbon nanotubes—single-walled, double-walled and multi-walled CNTs (SWCNTs, DWCNTs, MWCNTs)—were used to evaluate the effect of their morphology on electrical and electromechanical performance. SWCNT- and DWCNT-doped nanocomposites presented a higher Tg compared with MWCNT-doped nanocomposites due to a lower UV light shielding effect. This phenomenon also justifies the decrease of nanocomposite Tg with the increase of CNT content in every case. The electromechanical analysis reveals that SWCNT- and DWCNT-doped nanocomposites show a higher electromechanical performance than nanocomposites doped with MWCNTs, with a slight increment of strain sensitivity in tensile conditions, but also a significant strain sensitivity gain at bending conditions.

Persistent Luminescence Cr3+ Doped Spinels and Use as Biomarker for In Vivo Imaging

2014 ◽  
Vol 90 ◽  
pp. 157-165
Author(s):  
Suchinder K. Sharma ◽  
D. Gourier ◽  
B. Viana ◽  
T. Maldiney ◽  
E. Teston ◽  
...  
Keyword(s):  
Uv Light ◽  
Red Light ◽  
Band Gap Energy ◽  
Transparency Window ◽  
Persistent Luminescence ◽  
High Brightness ◽  
Mouse Imaging ◽  
Classical Quantum ◽  
Living Tissues

ZnGa2O4(ZGO) is a normal spinel. When doped with Cr3+ions, ZGO:Cr becomes a high brightness persistent luminescence material with an emission spectrum perfectly matching the transparency window of living tissues. It allowsin vivomouse imaging with a better signal to background ratio than classical quantum dots. The most interesting characteristic of ZGO:Cr lies in the fact that its LLP can be excited with red light, well below its band gap energy and in the transparency window of living tissues. A mechanism based on the trapping of carriers localized around a special type of Cr3+ions namely CrN2can explain this singularity. The antisite defects of the structure are the main responsible traps in the persistent luminescence mechanism. When located around Cr3+ions, they allow, via Cr3+absorption, the storage of not only UV light but also all visible light from the excitation source.

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