Synthesis of TiO2/Muti-Walled Carbon Nanotubes Composite

2010 ◽  
Vol 434-435 ◽  
pp. 546-548 ◽  
Author(s):  
Min Zhang ◽  
Na Zhang ◽  
Jing Chu ◽  
Jing Sun ◽  
Qiang Li

TiO2/Multi-walled carbon nanotubes (MWNTs) were prepared via a wet chemical route with hydrolysis of titanium salts. The purification and oxidation treatment of MWNTs in concentrated HNO3 solution were conducted to modify the nanotubes. Then the pre-treated carbon nanotubes were added into the titanium salt and in the end the composites were formed. The microstructure of as-prepared TiO2/MWNTs composite was studied by TEM. The samples were calcined at different temperature. By X-ray diffraction (XRD), the phase transformation of nano-structured TiO2 in composites was determined. The photocatalytic activity of samples being calcined at different temperature was studied by using the conversion of methyl orange in aqueous solutions as probe reaction. The influence of the structure on photocatalysis efficiency was discussed. By contrast with that of pure TiO2 nanoparticles, the special structure of TiO2/MWNT composite could remarkably improve the efficiency of the photocatalytic reaction. The results indicated that the excited e- in conduction band of TiO2 might transfer into MWNTs and the possibility of the recombination of e-/h+ pairs decreased.

2017 ◽  
Vol 76 (10) ◽  
pp. 2593-2602 ◽  
Author(s):  
Vahid Alimohammadi ◽  
Mehdi Sedighi ◽  
Ehsan Jabbari

Abstract This paper reports a facile method for removal of sulfate from wastewater by magnetic multi-walled carbon nanotubes (MMWCNTs). Multi-walled carbon nanotubes and MMWCNTs were characterized by X-ray diffraction, Raman, transmission electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometry. The results of the analysis indicated that MMWCNTs were synthesized successfully. The MMWCNTs can be easily manipulated in a magnetic field for the desired separation, leading to the removal of sulfate from wastewater. Response surface methodology (RSM) coupled with central composite design was applied to evaluate the effects of D/C (adsorbent dosage per initial concentration of pollutant (mgadsorbent/(mg/l)initial)) and pH on sulfate removal (%). Using RSM methodology, a quadratic polynomial equation was obtained, for removal of sulfate, by multiple regression analysis. The optimum combination for maximum sulfate removal of 93.28% was pH = 5.96 and D/C = 24.35. The experimental data were evaluated by the Langmuir and Freundlich adsorption models. The adsorption capacity of sulfate in the studied concentration range was 56.94 (mg/g). It was found out that the MMWCNTs could be considered as a promising adsorbent for the removal of sulfate from wastewater.


2010 ◽  
Vol 636-637 ◽  
pp. 714-721 ◽  
Author(s):  
K. Kordatos ◽  
A. Ntziouni ◽  
A. Theodoratou ◽  
Maria Perraki ◽  
M. Terrones ◽  
...  

The present work describes the synthesis of nitrogen doped multi-walled carbon nanotubes (CNx CNT). The chosen production method was the catalytic pyrolysis of a solid mixture containing [Ni(DMG)2] and melamine (C3H6N6), under an Αr atmosphere. A series of various experiments were performed, using different proportions of the reaction mixture, in order to optimize the production conditions of nitrogen doped carbon nanotubes. Finally, the produced materials were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), Raman spectroscopy as well as thermogravimetric analysis (TGA). The obtained data from all the above analyses, showed the formation of nitrogen doped carbon nanotubes of various diameters as well as nanofibers surrounded by byproducts such as aggregations of amorphous carbon and metallic catalyst, depending on the proportion of the reaction mixture.


2020 ◽  
Vol 30 ◽  
pp. 41-54
Author(s):  
Shelan A. Farman ◽  
Muayed K. Ibrahim ◽  
Kadhim A. Aadim

Nanocarbon structures such as graphene (GR), single-walled carbon nanotubes (SWCNTs) as well as the multi-walled carbon nanotubes (MWCNTs) were deposited on crystalline n-type silicon wafers to fabricate nanoCarbon-Si solar cells. Nanocarbon films deposited on glass and porous silicon (PS) via pulse laser deposition (PLD) with the use of Q-Switching Nd: YAG laser with λ=1064 (nm), Energy (E)=700 (mJ), Repetition rate (f)=6 (HZ) under vacuum condition with 2.5×10-2 (mbar). The surface morphology, structure, and optical Nanocarbon thin films have been examined with the use of X-ray Diffraction (XRD), Atomic force microscope (AFM), FTIR spectrophotometer and UV-visible. In addition, the power conversion efficiency that is related to the prepared solar cells is estimated through J-V characterization. The PCE of all Nanocarbon/PS follows the orders; SWCNTs/PS < MWCNTs/PS< GR/PS.


2018 ◽  
Vol 78 (5) ◽  
pp. 1001-1009 ◽  
Author(s):  
Chuyuan Ding ◽  
Jun He ◽  
Mengxia Xu ◽  
Chengjun Wang

Abstract In this work, the novel β-cyclodextrin modified mesostructured silica coated multi-walled carbon nanotubes (MWCNTs) composites were synthesized and applied for the removal of parabens in aqueous solution. The prepared MWCNTs/SiO2/β-CD composites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermogravimetric analysis. The effects of the amount of adsorbent, pH and elution solvents on the removal efficiency of parabens from water solutions were investigated. Under the optimized conditions, over 95% removal efficiency was achieved by using 40 mg of MWCNTs/SiO2/β-CD adsorbents to absorb the parabens from 60 mL of 0.5 μg/mL parabens solutions. The solution pH in the range from 5 to 9 has no influence on the removal efficiency and the parabens sorption capacity of the prepared adsorbents were around 0.75 μg/mg. Furthermore, the stability and reusability studies demonstrated that the prepared MWCNTs/SiO2/β-CD composites are cost-effective adsorbents for the removal of parabens from water with high regeneration efficiency. The composites fabricated in this study could become an attractive candidate for water purification.


2007 ◽  
Vol 52 (15) ◽  
pp. 2054-2062 ◽  
Author(s):  
CaiLing Fan ◽  
Wei Li ◽  
Xin Li ◽  
ShiJu Zhao ◽  
Ling Zhang ◽  
...  

2020 ◽  
Vol 98 (1) ◽  
pp. 49-55 ◽  
Author(s):  
María Fernanda Veloz-Castillo ◽  
Antonio Paredes-Arroyo ◽  
Gerardo Vallejo-Espinosa ◽  
José Francisco Delgado-Jiménez ◽  
Jeffery L. Coffer ◽  
...  

The growing interest in nanomaterials in different application fields calls for the implementation of simple, economically appealing, and efficient preparative methods. Among the wide variety of nanomaterials, carbon nanostructures have a special place due to their potential technological applications. Here, we present a fast, cheap, and easy-to-implement microwave-assisted method for the preparation of carbon nanotubes (CNTs) and carbon fibers (CFs) at room pressure conditions. The synthesis involves heating a mixture of graphite and ferrocene contained in a simple glass tube using a conventional microwave oven. A mixture of multi-walled carbon nanotubes (MWCNTs) and Fe3O4 magnetic nanoparticles were obtained quickly (less than 30 s) and in good yields. The products were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and Raman spectroscopy.


2011 ◽  
Vol 189-193 ◽  
pp. 1222-1227 ◽  
Author(s):  
Yuan Lian ◽  
Hong Mei Wang ◽  
Dian Wu Huang

Polypropylene (PP) nanocomposites with 0.1, 0.2, 0.5, 0.8, 1.0 and 2.0 wt% multi-walled carbon nanotubes (MW-CNTs) were prepared via meltcompounding in a twin-screw extruder followed by injection molding. The effects of MW-CNTs additions on the structure, mechanical and photo-oxidation behavior of PP were studied using X-ray diffraction (XRD), differential scanning calorimetry (DSC), tensile tests and FT-IR apparatus. XRD results showed that only α-PP crystals form in the PP/MW-CNTs composites. DSC results confirmed that the corporation of MW-CNTs enhanced the nucleation process on PP crystallization. Results of the tensile tests showed that before photo-oxidation, the tensile strengths of the samples increased with the increase of MW-CNTs contents when the MW-CNTs contents were less than 1% wt, whilst the tensile strength decreased at higher MW-CNTs contents (>1% wt). When subjected to photo-oxidation, the tensile strengths of the samples decreased with the increasing photo-oxidation time. The resistance to accelerated photo-oxidation of PP/MW-CNTs composites was also compared with the photo-oxidation behaviour of the original polypropylene sample. At short photo-oxidation time, such as under 250 h, the rates of carbonyl formation for the PP/MW-CNTs composites are similar to that observed for the original polypropylene but at longer photo-oxidation times the carbonyl formation increases for lower MW-CNTs contents (0.1, 0.2, 0.5 and 0.8% wt), and decreases for higher MW-CNTs contents (1 and 2% wt). It was found that the MW-CNTs showed both anti-degradation and pro-degradation effects at different concentrations.


2010 ◽  
Vol 117 ◽  
pp. 27-32
Author(s):  
Sabita Shrestha ◽  
Chong Yun Park

Titanium dioxide (Titania, TiO2) nanoparticles have been deposited on the surface of acid treated multi-walled carbon nanotubes (MWCNTs) by simple chemical route. The resultant TiO2/MWCNTs composites were characterized by different techniques. The oxidation of MWCNTs and presence of titania nanoparticles on the surface of MWCNTs is confirmed by transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. TEM image shows the size of titania nanoparticles are around 5 nm. Raman spectroscopy showed the oxidation and functionalization of nanotubes. The TGA curve showed decrease in thermal decomposition temperature of MWCNTs after oxidation and attachment with titania nanoparticles.


Author(s):  
Ulambayar R ◽  
Dawaabal B ◽  
Oyun-Erdene G ◽  
J Temuujin

Depending on the application, carbon nanotubes are being intensively studied in physics, chemistry, medicine, and computers. Therefore, it is important to develop large-scale high-quality multi-walled carbon nanotubes production at low cost. Wehere conducted a study on the easy preparation of low-cost carbon nanotubes. Two graphite electrodes were placed vertically in a thick, clear plastic container with distilled water to produce a carbon nanotube with an alternating current arc. The device has a simple design and the water acts as an insulating medium and cools the system. X-ray diffraction (XRD) and infrared spectrum (FTIR) analysis of the obtained carbon soot was performed in comparison with technical multi-walled carbon nanotubes. These tests confirmed that the multi-walled carbon nanotubes were formed during the experiment. Нуман цахилалтын аргаар усан орчинд нүүрстөрөгчийн нано хоолой гарган авах урьдчилсан судалгаа Хураангуй: Нүүрстөрөгчийн нано хоолойг хэрэглээнээс хамаарч физик, хими, анагаах ухаан, компьютер гэх зэрэг салбаруудад эрчимтэй судлаж байна. Иймээс ч өндөр чанартай олон ханатай нүүрстөрөгчийн нано хоолойг бага зардлаар их хэмжээтэй, гарган авах арга техникийг хөгжүүлэх нь нэн чухал юм. Бид бага зардлаар нүүрстөрөгчийн нано хоолойг хялбараар гарган авах судалгааг явууллаа. Нэрмэл ус бүхий зузаан тунгалаг хуванцар саванд бал чулуун хоёр электродыг босоо хэлбэртэй байрлуулан хооронд нь хувьсах гүйдлийн нуман цахилалт цахилуулан нүүрстөрөгчийн нано хоолойг гарган авсан. Энэхүү төхөөрөмж нь энгийн хялбар хийцтэй бөгөөд ус нь тусгаарлагч орчин болж, системийг хөргөдөг. Гарган авсан нүүрстөрөгчийн хөөнд рентген дифракцийн (XRD) болон нил улаан туяаны спектрийн (FTIR) шинжилгээг техникийн олон ханатай нүүрстөрөгчийн нано хоолойтой харьцуулан хийж гүйцэтгэсэн. Эдгээр шинжилгээгээр олон ханатай нүүрстөрөгчийн нано хоолой туршилтын явцад үүссэн болохыг баталлаа. Түлхүүр үг: Нуман цахилалт, нүүрстөрөгчийн нано хоолой, графен, графит (бал чулуу)


Sign in / Sign up

Export Citation Format

Share Document