Synthesis of TiO2/RGO Nanocomposites by Hydrothermal Method and their Photocatalytic Activity Research

2015 ◽  
Vol 814 ◽  
pp. 178-181
Author(s):  
Jin Feng Leng ◽  
Ying Zi Wang ◽  
Xin Ying Teng ◽  
De Jiang Hu

The TiO2 reduced graphene oxide (TiO2/RGO) nanocomposites were synthetized by hydrothermal method. The microstructure and morphologies of them were characterized by XRD and SEM. The photocatalytic activity was investigated by the methyl orange photogradation under UV illumination. The results showed that GO sheets had wrinkles and folds, and anatase-structured TiO2 covered on graphene surface after hydrothermal reaction. Compared to the TiO2 nanoparticles, the TiO2/RGO nanocomposites display the higher photogradation efficiency. In 90 minutes, the gradation percentage of TiO2/RGO nanocomposites to methyl orange is 80%, higher than TiO2 nanoparticle (40%). This is attributed to the large surface area of TiO2/RGO nanocomposites and their improved separation efficiency of electron-hole pair.

2019 ◽  
Vol 19 (11) ◽  
pp. 7089-7096 ◽  
Author(s):  
Wufa Li ◽  
Xiaohong Yang ◽  
Haitao Fu ◽  
Xizhong An ◽  
Haiyang Zhao

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.


2017 ◽  
Vol 6 (6) ◽  
pp. 505-516 ◽  
Author(s):  
Hongguang Yu ◽  
Chenglin Chu ◽  
Paul K. Chu

AbstractThe reduced graphene oxide-Bi2WO6 (rGO-BWO) photocatalysts with different RM values (mass ratio of GO and Bi2WO6) had been successfully synthesized via hydrothermal method in the presence of GO. When increasing the RM values from 0 to 2%, the evident red shift of the absorption edges of rGO-BWO samples occurred, and the photocatalytic activities for the degradation of Rhodamine-B were enhanced gradually. However, there was a significant blue shift in the absorbance band, and the morphology of the incomplete rGO-BWO microspheres led to the lower photocatalytic activity when RM is increased from 4 to 10%. The enhanced photocatalytic activity can be attributed to the smaller band gap, which means needing less energy for the electron transition, the morphology of the unbroken microsphere that provides more possible reaction sites for the photocatalytic reaction, the appropriate GO content that may effectively mitigate electron-hole pair recombination by the migration of photoinduced electrons.


NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650114 ◽  
Author(s):  
Dan Li ◽  
Jianwei Li ◽  
Caiqin Han ◽  
Xinsheng Zhao ◽  
Haipeng Chu ◽  
...  

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180[Formula: see text]C exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.


2011 ◽  
Vol 197-198 ◽  
pp. 919-925 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu

Silver (Ag+) doped iron (III) vanadate (FeVO4) samples are prepared by the precipitation method and then characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy(XPS). The photocatalytic activity under visible light is evaluated by photocatalytic degradation of methyl orange (MO) in the solution. The results show that both FeVO4 and Ag+ doped FeVO4 samples are triclinic, the later have different surface morphology, and some needle-shaped materials appear in the later. From XPS, there are more Fe2+ ions in Ag+ doped FeVO4 sample than that in FeVO4 one without Ag+. It indicates that Ag+ doping can increase the density of the surface oxygen vacancies of catalysts, which can act as electron traps promoting the electron-hole separation and then increase the photo-activity. The decoloration rate after Ag+ doping against methyl orange solution can reach about 81%, and be more about 20% than that of pure FeVO4.


RSC Advances ◽  
2016 ◽  
Vol 6 (92) ◽  
pp. 89687-89698 ◽  
Author(s):  
Gabriela Byzynski Soares ◽  
Renan Augusto Pontes Ribeiro ◽  
Sergio Ricardo de Lazaro ◽  
Caue Ribeiro

In N-doping on TiO2 nanomaterial occurs a big decrease of band-gap (1 eV); however, its photocatalysis is low. We clarify such fact from effective mass, i.e., the electron–hole recombination is more than creation of electron–hole pair.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Pham Van Viet ◽  
Cao Minh Thi ◽  
Le Van Hieu

Tin oxide nanoparticles (SnO2NPs) were prepared at low temperature by hydrothermal method. Synthesized SnO2NPs were confirmedviacharacterization techniques such as UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and Transmission Electron Microscope (TEM). The synthesized nanoparticles were in the size of 3 nm and they have high photocatalytic activity. The result showed that SnO2NPs degraded 88.88% MB solution after 30 minutes of UV illumination and reached 90.0% for 120 minutes (2 hours) of UV illumination. Moreover, they degraded 79.26% MB solution after 90 minutes (1.5 hours) under assisted sunlight illumination.


2007 ◽  
Vol 534-536 ◽  
pp. 105-108
Author(s):  
Zhong Qing Liu ◽  
Zheng Hua Li ◽  
Yan Ping Zhou ◽  
Chang Chun Ge

The Ag/TiO2-xNx nanoparticles were synthesized by photochemical deposition with irradiation of visible light in a TiO2-XNX suspension system. The prepared products were characterized by means of XRD, Uv-vis, and FEM. Its photocatalytic activity was investigated by the decomposition of methylene blue (MB) solution under illumination of visible and ultraviolet light, respectively. Compared to TiO2-xNx, the photocatalytic activity of as–prepared Ag/TiO2-xNx is obviously enhanced due to the decreasing recombination of a photoexcited electron-hole pair. The mechanism in which photocatalytic activity is enhanced is discussed in detail.


RSC Advances ◽  
2016 ◽  
Vol 6 (65) ◽  
pp. 60318-60326 ◽  
Author(s):  
Long Zhang ◽  
Lan Sun ◽  
Shuai Liu ◽  
Yuhong Huang ◽  
Kewei Xu ◽  
...  

The MoS2/rGO exhibits enhanced photocatalytic activity for degradation of RhB due to effective separation of photo-generated electron–hole pairs by heterointerface.


RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27933-27939 ◽  
Author(s):  
Qingyan Nong ◽  
Min Cui ◽  
Hongjun Lin ◽  
Leihong Zhao ◽  
Yiming He

The coupling of FeVO4 nanorods with g-C3N4 promotes the separation efficiency of photogenerated electron–hole pairs, and subsequently enhances its photocatalytic activity in rhodamine photodegradation.


2018 ◽  
Vol 6 (3) ◽  
pp. 1102-1108 ◽  
Author(s):  
Haiguang Zhu ◽  
Nirmal Goswami ◽  
Qiaofeng Yao ◽  
Tiankai Chen ◽  
Yanbiao Liu ◽  
...  

We decorated per-6-thio-β-cyclodextrin protected gold nanoclusters on TiO2 nanoparticles to improve photocatalytic activity by inhibiting electron–hole pair recombination and absorbing organic targets via host–guest interactions.


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