scholarly journals Multiwalled Carbon Nanotube-TiO2Nanocomposite for Visible-Light-Induced Photocatalytic Hydrogen Evolution

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ke Dai ◽  
Xiaohu Zhang ◽  
Ke Fan ◽  
Peng Zeng ◽  
Tianyou Peng
Keyword(s):  
Carbon Nanotube ◽  
Visible Light ◽  
Hydrogen Generation ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
Multiwalled Carbon Nanotube ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Intimate Contact ◽  
Adsorption Desorption

Multiwalled carbon nanotube- (MWCNT-) TiO2nanocomposite was synthesized via hydrothermal process and characterized by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, field emission scanning electron microscope, thermogravimetry analysis, and N2adsorption-desorption isotherms. Appropriate pretreatment on MWCNTs could generate oxygen-containing groups, which is beneficial for forming intimate contact between MWCNTs and TiO2and leads to a higher thermal stability of MWCNT-TiO2nanocomposite. Modification with MWCNTs can extend the visible-light absorption of TiO2. 5 wt% MWCNT-TiO2derived from hydrothermal treatment at 140°C exhibiting the highest hydrogen generation rate of 15.1 μmol·h−1under visible-light irradiation and a wide photoresponse range from 350 to 475 nm with moderate quantum efficiency (4.4% at 420 nm and 3.7% at 475 nm). The above experimental results indicate that the MWCNT-TiO2nanocomposite is a promising photocatalyst with good stability and visible-light-induced photoactivity.

Preparation, Characterization and Photocatalytic Activity of F, Fe-Codoped Nano-TiO2

2013 ◽  
Vol 448-453 ◽  
pp. 169-173
Author(s):  
Chun Yan Yan ◽  
Wen Tao Yi
Keyword(s):  
Photocatalytic Activity ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Hydrothermal Process ◽  
Neutral Red ◽  
Reaction Model ◽  
X Ray Diffraction ◽  
Pseudo First Order Reaction ◽  
Adsorption Desorption ◽  
Desorption Method

Pure and F, Fe-codoped TiO2 were prepared by sol-hydrothermal process, in which titanium (IV) n-butoxide, Fe (NO3)2·6H2O and NH4F were used as precursors. And the samples were characterized by X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS), scanning electron microscopy (SEM), and N2 adsorption-desorption method. The results showed that the F, Fe-codoped samples were principally single-phase anatase structures, and the particles possessed higher BET area than that of pure TiO2. The photocatalytic activity and reusability of the catalysts under UV light (365nm) was investigated with neutral red as the model compound. The results showed that F (2.0%), Fe (4.0%) codoped TiO2 had the highest photocatalytic activity among all as-prepared samples. The kinetic study showed that this photocatalytic process coincided with the Langmuir-Hinshelwood (L-H) pseudo first order reaction model.

The Preparation and Characterization of Polybenzoxazole Copolymerized with Multiwalled Carbon Nanotube via Direct Friedel-Crafts Acylation

2014 ◽  
Vol 989-994 ◽  
pp. 560-563
Author(s):  
Yong Chen ◽  
Jun Qian ◽  
Qi Xin Zhuang ◽  
Zhe Wen Han
Keyword(s):  
Carbon Nanotube ◽  
Polyphosphoric Acid ◽  
Multiwalled Carbon Nanotube ◽  
X Ray Diffraction ◽  
Acylation Reaction ◽  
Multiwalled Carbon ◽  
Sem Images ◽  
X Ray ◽  
Electronic Microscope

Multiwalled carbon nanotube (MWCNT) was subjected a copolymerization reaction with 4, 6-diaminoresorcinol salt (DAR•2HCl) and terephthalic acid (TA) in polyphosphoric acid (PPA) by Friedel-Crafts acylation reaction without any acid treatment or modification. The structure and morphology of the as-prepared poly (p-phenylene benzobisoxazole) (PBO)/MWCNT nanocomposites were characterized by X-ray diffraction (XRD) and scanning electronic microscope (SEM). The SEM images indicated that MWCNTs can disperse in PBO matrix uniformly without agglomeration and MWCNTs have been introduced into PBO matrix by covalent bonding via Friedel-Crafts acylation between MWCNTs and TA.

Synthesis of Nanocrystalline InVO4 by Hydrothermal Process and its Visible-Light Photocatalytic Activity

2011 ◽  
Vol 284-286 ◽  
pp. 734-737 ◽  
Author(s):  
Pei Song Tang ◽  
Hai Feng Chen ◽  
Feng Cao ◽  
Guo Xiang Pan ◽  
Kun Yan Wang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Light Absorption ◽  
Diffuse Reflectance Spectroscopy ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Visible Light Absorption ◽  
Visible Light Photocatalytic Activity ◽  
Hydrothermal Approach ◽  
Visible Light Photocatalytic

Monophasic orthorhombic InVO4 was synthesized using InCl3 and NH4VO3 as starting materials by a hydrothermal approach. The as-prepared InVO4 product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). It was found that the as-prepared InVO4 shows strong visible-light absorption with absorption onset of 515 nm, indicating a narrow optical band gap of 2.4 eV. Furthermore, the as-prepared InVO4 shows high visible-light photocatalytic activity for decomposition of methyl orange, which is ascribed to the strong visible-light absorption.

scholarly journals Synthesis of porous LaFeO3 prepared by nanocasting method for photo-Fenton degradation of oily-containing wastewater

2021 ◽  
Vol 11 (1) ◽  
pp. xx-xx
Author(s):  
Nga Phan To ◽  
Lien Nguyen Hong ◽  
Tuyen Le Van ◽  
Nhan Phan Chi ◽  
Huyen Phan Thanh
Keyword(s):  
Electron Microscopy ◽  
Catalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Transmission Electron ◽  
Visible Light Driven ◽  
Adsorption Desorption

Porous LaFeO3 were synthesised by nanocasting method using mesoporous silica (SBA-15) as a hard template and used as a visible-light-driven photocatalyst. The as-synthesised LaFeO3 photocatalyst were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray Diffraction (XRD), N2 adsorption-desorption, and Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV-vis DRS). The photo-Fenton catalytic activities of porous LaFeO3 were investigated for the degradation of oily-containing wastewater. The results showed that porous LaFeO3 had better photo-Fenton catalytic activity under visilbe light irradiation than pure LaFeO3. The remarkable improvement photo-Fenton catalytic activity of porous LaFeO3 material could be attributed to the synergistic effect of adsorption and visible light photo-Fenton processes thanks to its porous structure.

scholarly journals Elucidating How Surface Functionalization of Multiwalled Carbon Nanotube Affects Nanostructured MWCNT/Titania Hybrid Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Cheng-Fu Yang ◽  
Wei-Chieh Hsu ◽  
Song-Mao Wu ◽  
Chean-Cheng Su
Keyword(s):  
Carbon Nanotube ◽  
Sol Gel ◽  
Multiwalled Carbon Nanotube ◽  
Acyl Chloride ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Functionalized Mwcnts

The new class of multiwalled carbon nanotube (MWCNT)/titania nanocomposites was prepared using a sol-gel technique. The addition of titania to MWCNTs has the potential to provide new capability for the development of electrical devices by taking advantage of the favorable electric characteristics of MWCNTs. MWCNTs were first functionalized with carboxyl, acyl chloride, amine, and hydroxyl groups and were then dispersed in a tetraisopropyl titanate (TIPT) solution via ultrasonic processing. After gelation, well-dispersed titania in the MWCNT/titania nanocomposites was obtained. Functionalized MWCNTs with varied functional groups were proved by Fourier transform infrared spectroscopy (FT-IR). For the nanocomposites, the degree of the sol-gel process were proved by Raman spectroscopy and wide-angle X-ray diffraction (WAXD). Furthermore, the morphology of the MWCNT/titania nanocomposites was observed using transmission electron microscopy (TEM). In the sol-gel process, the functionalized MWCNTs with carboxyl, acyl chloride, amine, and hydroxyl groups have resulted in the carbon nanotube-graft-titania nanocomposites with a network structure of titania between the carbon nanotubes.

Preparation of TiO2/Multiwalled Carbon Nanotube Composites and Their Applications in Photocatalytic Reduction of Cr(VI) Study

2008 ◽  
Vol 8 (11) ◽  
pp. 5624-5631 ◽  
Author(s):  
Xiaoli Tan ◽  
Ming Fang ◽  
Xiangke Wang
Keyword(s):  
Carbon Nanotube ◽  
Photoelectron Spectroscopy ◽  
Ternary Systems ◽  
Photocatalytic Reduction ◽  
Multiwalled Carbon Nanotube ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Nanotube Composites ◽  
A Minor

The TiO2/multiwalled carbon nanotube (MWCNT) composites were prepared by hydrothermal deposition. Batch experiments were carried out to study the removal of Cr(VI) from aqueous solution to TiO2, MWCNTs and TiO2/MWCNTs. Scanning electron microscopy and X-ray diffraction were utilized to characterize the prepared TiO2/MWCNT composites. The introduction of MWCNTs onto TiO2 catalyst led to a remarkable increase of Cr(VI) removal through adsorption and photocatalytic reduction under ultraviolet irradiation. Results of X-ray photoelectron spectroscopy analysis of chromium species adsorbed on TiO2/MWCNTs phase revealed that the removal mechanism of Cr(VI) by TiO2/MWCNTs under UV-irradiation was the reduction of Cr(VI) into Cr(III). The adsorption and photocatalytic activity of Cr(VI) decreased with increasing in pH, and was not affected by the concentration of sulphate obviously. In the ternary systems humic acid (HA)/fulvic acid (FA)-Cr(VI)-TiO2/MWCNTs, the increasing of FA/HA concentration did not cause any drastic changes in the adsorption capacity in terms of Cr(VI) concentration in the dark, but a minor increasing trend for the photocatalytic reduction of Cr(VI). The presence of humic substances enhanced the photocatalytic reduction and adsorption of Cr(III) to TiO2/MWCNTs.

scholarly journals Enhanced Degradation of Rhodamine B by Metallic Organic Frameworks Based on NH2-MIL-125(Ti) under Visible Light

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7741
Author(s):  
Hong-Tham Nguyen Thi ◽  
Kim-Ngan Tran Thi ◽  
Ngoc Bich Hoang ◽  
Bich Thuy Tran ◽  
Trung Sy Do ◽  
...  
Keyword(s):  
Visible Light ◽  
Rhodamine B ◽  
Diffuse Reflectance ◽  
High Efficiency ◽  
Diffuse Reflectance Spectroscopy ◽  
Active Species ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fundamental Properties ◽  
Adsorption Desorption

Samples of the bimetallic-based NH2-MIL-125(Ti) at a ratio of Mn+/Ti4+ is 0.15 (Mn+: Ni2+, Co2+ and Fe3+) were first synthesized using the solvothermal method. Their fundamental properties were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectra, scanning electron microscopy (SEM), N2 adsorption–desorption measurements, and UV–Vis diffuse reflectance spectroscopy (UV-Vis DRS). The as-acquired materials were used as high-efficiency heterogeneous photocatalysts to remove Rhodamine B (RhB) dye under visible light. The results verified that 82.4% of the RhB (3 × 10−5 M) was degraded within 120 min by 15% Fe/Ti−MOFs. Furthermore, in the purpose of degrading Rhodamine B (RhB), the rate constant for the 15% Fe/Ti-MOFs was found to be 2.6 times as fast as that of NH2-MIL-125(Ti). Moreover, the 15% Fe/Ti-MOFs photocatalysts remained stable after three consecutive cycles. The trapping test demonstrated that the major active species in the degradation of the RhB process were hydroxyl radicals (HO∙) and holes (h+).

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