scholarly journals Improved photocatalytic activity of anatase titanium dioxide by reduced graphene oxide

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Nor Shuhada Alim ◽  
Hendrik O. Lintang ◽  
Leny Yuliati
Keyword(s):  
Titanium Dioxide ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Uv Light ◽  
Electronic Conductivity ◽  
Anatase Tio2 ◽  
Electron Hole ◽  
Reduced Graphene ◽  
Xrd Patterns ◽  
Hole Recombination

Reduced graphene oxide (rGO) has been one of the most investigated carbon based materials due to its great electronic conductivity that make it able to accept and transport electron easily. In order to study the effect of rGO, anatase titanium dioxide-reduced graphene oxide (TiO2-rGO) composite was prepared by UV-assisted photocatalytic reduction method using the anatase TiO2 as a photocatalyst and various different loadings of graphene oxide (GO). The characterizations of the prepared samples were investigated by X-ray diffractometer (XRD), Fourier transform infrared (FTIR), and fluorescence spectroscopies. The XRD patterns and FTIR spectra confirmed that all the TiO2-rGO composites samples were successfully synthesized without disrupting the structure of the anatase TiO2. Fluorescence spectroscopy revealed the role of the rGO to reduce the electron-hole recombination on the anatase TiO2. In the photocatalytic removal of phenol, all the TiO2-rGO composites showed better photocatalytic activities than the bare anatase TiO2 under UV light irradiation. The activity of the anatase TiO2 was enhanced by more than four times with the addition of the GO with the optimum amount (3 wt%). It was proposed that the good photocatalytic performance obtained on the composites were caused by the successful suppression of electron-hole recombination by the rGO on the TiO2.

Synthesis of TiO2-Reduced Graphene Oxide Nanocomposites Offering Highly Enhanced Photocatalytic Activity

2019 ◽  
Vol 19 (11) ◽  
pp. 7089-7096 ◽  
Author(s):  
Wufa Li ◽  
Xiaohong Yang ◽  
Haitao Fu ◽  
Xizhong An ◽  
Haiyang Zhao
Keyword(s):  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Environmental Remediation ◽  
Hydrothermal Reaction ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
Hole Recombination

Photogenerated electron–hole recombination significantly restricts the catalytic efficiency of titanium dioxide (TiO2). Various approaches have been developed to overcome this problem, yet it remains challenging. Recently, graphene modification of TiO2 has been considered as an effective alternative to prevent electron–hole recombination and consequently enhance the photocatalytic performance of TiO2. This study reports an efficient but simple hydrothermal method utilizing titanium (IV) butoxide (TBT) and graphene oxide (GO) to prepare TiO2-reduced graphene oxide (RGO) nanocomposites under mild reaction conditions. This method possesses several advantageous features, including no requirement of high temperature for TiO2 crystallization and a one-step hydrothermal reaction for mild reduction of GO without a reducing agent, which consequently makes the production of TiO2-RGO nanocomposites possible in a green and an efficient synthetic route. Moreover, the as-synthesized nanocomposites were characterized by numerous advanced techniques (SEM, TEM, BET, XRD, XPS, and UV-vis spectroscopy). In particular, the photocatalytic activities of the synthesized TiO2-RGO nanocomposites were evaluated by degrading the organic molecules (methylene blue, MB), and it was found that the photocatalytic activity of TiO2-RGO nanocomposites is ~4.5 times higher compared to that of pure TiO2. These findings would be useful for designing reduced graphene oxide-metal oxide hybrids with desirable functionalities in various applications for energy storage devices and environmental remediation.

scholarly journals Synthesis of Titanium Dioxide Nanotubes with Different N-Containing Ligands via Hydrothermal Method

2021 ◽  
Vol 6 (2) ◽  
pp. 67-73
Author(s):  
Cheng Yee Leong ◽  
Ye Shen Lo ◽  
Pei Wen Koh ◽  
Siew Ling Lee
Keyword(s):  
Titanium Dioxide ◽  
Hydrothermal Method ◽  
Tio2 Nanotubes ◽  
Uv Light ◽  
Anatase Phase ◽  
Anatase Tio2 ◽  
Molar Ratio ◽  
Electron Hole ◽  
Tauc Plot ◽  
Hole Recombination

Titanium dioxide (TiO2) nanotubes (TNT) were successfully synthesized using different N-containing ligands via hydrothermal method. Methylamine, ethylenediamine and diethylenetriamine with different Ti/ligand molar ratios (1:1, 1:3, 1:5 and 1:8) were prepared. As-synthesized TiO2 without N-containing ligands were also prepared for comparison purpose. The X-Ray Diffraction patterns confirmed the presence of anatase phase of TiO2 in all the synthesized samples whereas the presence of sodium titanate was only detected in the samples containing N-containing ligands. The Transmission Electron Microscopy images also showed that the N-containing ligands promoted the formation of nanotubes in the anatase TiO2. Based on the Tauc Plot, the band gap energy of anatase TiO2 was shifted with the addition of methylamine, ethylenediamine and diethylenetriamine. The photoluminescence spectra also showed that with the addition of sufficient amount of N-containing ligands, the intensity of photoluminescence spectrum decreased, suggesting formation of more nanotube and reduction of electron hole recombination rate. The photocatalytic performance of all synthesized samples was determined through photodegradation of Congo red under UV light for 6 hours. The results suggested that among the synthesized materials, the sample which contained diethylenetriamine with molar ratio of 5 gave the highest photocatalytic activity of 76.71% which could be attributed to successful formation of nanotube, its higher surface rate reaction and low electron hole recombination. Diethylenetriamine showed higher efficiency in assisting the formation of TiO2 nanotubes compared to methylamine and ethylenediamine.

scholarly journals Improved electron–hole separation and migration in anatase TiO2 nanorod/reduced graphene oxide composites and their influence on photocatalytic performance

Nanoscale ◽  
2017 ◽  
Vol 9 (13) ◽  
pp. 4578-4592 ◽  
Author(s):  
Gregor Žerjav ◽  
Muhammad Shahid Arshad ◽  
Petar Djinović ◽  
Ita Junkar ◽  
Janez Kovač ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photocatalytic Performance ◽  
Anatase Tio2 ◽  
Charge Migration ◽  
Electron Hole ◽  
Reduced Graphene ◽  
And Migration ◽  
Oxide Composites ◽  
Graphical Illustration

A graphical illustration of TNR + rGO composites and a possible mechanism for improved charge migration.

scholarly journals Photocatalytic Efficiency of Hybrid Titanium Dioxide Nanowires/Reduced Graphene Oxide (TiO2NWs/RGO) for Degradation of Methyl Orange Dye

2022 ◽  
Vol 34 (2) ◽  
pp. 395-401
Author(s):  
B.H. Azam ◽  
M.A.F. Md Fauzi ◽  
M.H. Razali
Keyword(s):  
Titanium Dioxide ◽  
Graphene Oxide ◽  
Methyl Orange ◽  
Reduced Graphene Oxide ◽  
Dye Degradation ◽  
Uv Light ◽  
Photocatalytic Efficiency ◽  
Reduced Graphene ◽  
Mobility Of Charge Carriers ◽  
Hybrid Photocatalyst

The aim of this research is to improve the photocatalytic efficiency by implementation of titanium dioxide nanowires/reduced graphene oxide (TiO2NWs/RGO) hybrid photocatalyst for dye degradation. The hybrid photocatalyst TiO2NWs/RGO was prepared using fabrication method. The physico-chemical properties of the photocatalyst was investigated by FTIR, XRD, SEM TGA, BET and their photocatalytic efficiency was evaluated for methyl orange degradation. Almost 100% of methyl orange was degraded by TiO2NWs/RGO hybrid photocatalyst under UV light within 210 min using 1.0 g at initial concentration of methyl orange were 10 and 20 ppm. This is due to the 1D/2D heterostructures of TiO2NWs/RGO hybrid photocatalyst that leads to the larger surface area, unique morphological and crystallinity properties, as well as excellent mobility of charge carriers and thermally stable structure

Preparation of TiO2-Reduced Graphene Oxide Nanocomposites for Sunlight Degradation of Methylene Blue

2018 ◽  
Vol 937 ◽  
pp. 17-23
Author(s):  
Wu Fa Li ◽  
Xiao Hong Yang ◽  
Hai Tao Fu ◽  
Xi Zhong An
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Reduction Process ◽  
Photogenerated Electron ◽  
Electron Hole ◽  
Reduced Graphene ◽  
One Step ◽  
Hole Recombination

Photogenerated electron/hole recombination greatly limits the catalytic efficiency of TiO2, and recently modification with graphene substance has been regarded as an effective way to enhance the photocatalytic performance of TiO2. When referring to the fabrication of graphene based materials, the reduction process of graphene oxide has been demonstrated to be a key step. Therefore, it is highly required to develop an efficient and simple route for the GO reduction and the formation of TiO2-reduced graphene oxide (RGO) nanocomposites. In this study, TiO2-RGO nanocomposites were prepared by a facile and efficient one-step hydrothermal method using titanium (IV) butoxide (TBT) and graphene oxide (GO) without reducing agents. This method shows several unique features, including no requirement of harsh chemicals and high temperature involved, one-step hydrothermal reaction for mild reduction of GO and crystallization of TiO2 running in parallel, and the production of TiO2-RGO nanocomposites in a green and efficient synthetic route. In addition, the photocatalytic activities of the synthesized composites were systematically evaluated by degrading methylene blue (MB) under sun light irradiation. The TiO2-RGO nanocomposites show a superior photocatalytic activity to the synthesized pure TiO2. It is also found that the concentration of RGO in the nanocomposites plays a key role in the photocatalytic activity. Specifically, the composite with 1 wt % RGO shows the best photocatalytic activity, probably due to the reduction of the electron-hole recombination rate.

Sign in / Sign up

Export Citation Format

Share Document