Nanocrystalline CNT-TiO2 Composites Produced by an Acid Catalyzed Sol-Gel Method

2008 ◽  
Vol 587-588 ◽  
pp. 849-853 ◽  
Author(s):  
Cláudia G. Silva ◽  
Wen Dong Wang ◽  
Joaquim L. Faria
Keyword(s):  
Carbon Nanotube ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Absorption Properties ◽  
Interphase Interaction ◽  
Gel Method ◽  
Sol Gel Method ◽  
Composite Catalysts ◽  
Acid Catalyzed

Carbon nanotube-TiO2 composites and pure TiO2 are prepared by a modified sol-gel method. The nanoscaled materials obtained are extensively characterized by spectroscopic, microscopic and calorimetric techniques. Their photoactivity is tested in the degradation of phenol under visible illumination. A correlation between the CNT content and the changes in the UV–vis absorption properties was found. The effect induced by CNT on the composite catalysts is explained in terms of an interphase interaction between CNT and TiO2 in the composite catalysts.

Visible light photodegradation of phenol on MWNT-TiO2 composite catalysts prepared by a modified sol–gel method

2005 ◽  
Vol 235 (1-2) ◽  
pp. 194-199 ◽  
Author(s):  
Wendong Wang ◽  
Philippe Serp ◽  
Philippe Kalck ◽  
Joaquim Luís Faria
Keyword(s):  
Visible Light ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Composite Catalysts

scholarly journals Broadband antireflective coating stack based on mesoporous silica by acid-catalyzed sol-gel method for concentrated photovoltaic application

2018 ◽  
Vol 186 ◽  
pp. 154-164 ◽  
Author(s):  
Cecilia Agustín-Sáenz ◽  
José Ángel Sánchez-García ◽  
Maider Machado ◽  
Marta Brizuela ◽  
Oihana Zubillaga ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Sol Gel ◽  
Antireflective Coating ◽  
Gel Method ◽  
Sol Gel Method ◽  
Photovoltaic Application ◽  
Acid Catalyzed

Nano-Sized Lithium Manganese Phosphate/Carbon Nanotube Composites with Enhanced Electrochemical Activity for Lithium-Ion Batteries

2012 ◽  
Vol 1440 ◽  
Author(s):  
Satoru Tsumeda ◽  
Scott D. Korlann ◽  
Shunzo Suematsu ◽  
Kenji Tamamitsu
Keyword(s):  
Electron Microscope ◽  
Carbon Nanotube ◽  
Lithium Ion Batteries ◽  
Sol Gel ◽  
Lithium Ion ◽  
Electrochemical Activity ◽  
Gel Method ◽  
Sol Gel Method ◽  
Manganese Phosphate ◽  
Lithium Manganese Phosphate

ABSTRACTOlivine lithium manganese phosphate, LiMnPO4 is a promising cathode material for high energy and safe lithium ion batteries. However, LiMnPO4 possesses excessively poor electrochemical activity, compared to conventional cathode materials. To enhance the electrochemical activity, we have synthesized LiMnPO4/multi-walled carbon nanotube (MWCNT) composites by employing an in-situ sol-gel method. The LiMnPO4/MWCNT composites were investigated by utilizing X-ray diffraction, thermogravimetric analysis, scanning electron microscope, transmission electron microscope, and galvanostatic charge-discharge cycling. The LiMnPO4 showed a particle size of ca. 50 nm and capacity of 102 mAh/g at 0.1 C without C.V. charging mode. This study demonstrated that the electrochemical activity of LiMnPO4 was significantly affected by not only pH and the amount of a chelating agent but also unreacted Mn2+. This is the first report analyzing the existence and effects of unreacted Mn2+ in LiMnPO4 synthesized by a sol-gel method.

scholarly journals Preparation and Characterization of CuFe2O4 Nanoparticles by the Sol-Gel Method and Investigation of Its Microwave Absorption Properties at Ku-Band Frequency Using Silicone Rubber

Proceedings ◽  
2018 ◽  
Vol 2 (17) ◽  
pp. 1155 ◽  
Author(s):  
Reza Peymanfar ◽  
Farzaneh Azadi ◽  
Yousef Yassi
Keyword(s):  
Microwave Absorption ◽  
Silicone Rubber ◽  
Electromagnetic Waves ◽  
Sol Gel ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Band Frequency ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ku Band

Recently, using microwave devices that emit electromagnetic waves and enhance the convenience of life have increased; however, they can be harmful to the environment. In this study, CuFe2O4 nanoparticles were prepared through the conventional sol-gel procedure and then were characterized by X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), and vector network analyzer (VNA) using S parameters. Results illustrated that pure crystal structure of magnetic nanoparticles has been synthesized by the sol-gel method with magnetic saturation (Ms) of 22 emu/g. Finally, CuFe2O4 nanoparticles were composited by silicone rubber to investigate its microwave absorption properties. Results showed that the CuFe2O4/silicone rubber nanocomposite absorbed more than 94.87% of the microwave irradiation at ku-band frequency with 1.7 mm thickness and the maximum reflection loss was −60.38 dB at 16.1 GHz. Magnetic and dielectric properties of the CuFe2O4 nanoparticles and silicone rubber polymeric matrix in the nanocomposite demonstrated desirable microwave absorption properties.

scholarly journals Preparation of sponge-like porous SiO2antireflective coatings with excellent environment-resistance by an acid-catalysed sol–gel method

RSC Advances ◽  
2017 ◽  
Vol 7 (43) ◽  
pp. 26834-26838 ◽  
Author(s):  
Bibo Xia ◽  
Jianhui Luo ◽  
Yuanyang Li ◽  
Bowen Yang ◽  
Shuming Zhang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Silica Coatings ◽  
Resistance Property ◽  
Acid Catalyzed

Silica coatings with high-transmittance and excellent environment-resistance property were prepared by adding hexamethyldisilazane (HMDS) into acid-catalyzed through sol–gel method.

scholarly journals THE PROPERTIES OF CADMIUM OXIDE-CARBON NANOTUBE NANOCOMPOSITE SYNTHESIZED VIA SOL-GEL METHOD

2019 ◽  
Vol 9 (1) ◽  
pp. 25-36
Author(s):  
Ömer Güler ◽  
Öyküm Başgöz ◽  
Muhammet Gökhan Albayrak ◽  
Mehmet Takgün
Keyword(s):  
Carbon Nanotube ◽  
Sol Gel ◽  
Cadmium Oxide ◽  
Gel Method ◽  
Sol Gel Method

scholarly journals Mixed Metal Oxides of M1 MoVNbTeOx and TiO2 as Composite Catalyst for Oxidative Dehydrogenation of Ethane

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Yuxin Chen ◽  
Dan Dang ◽  
Binhang Yan ◽  
Yi Cheng
Keyword(s):  
Metal Oxides ◽  
Oxidative Dehydrogenation ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Mixed Metal Oxides ◽  
Gel Method ◽  
Mixed Metal ◽  
Sol Gel Method ◽  
Composite Catalysts ◽  
Oxidative Dehydrogenation Of Ethane

Composite catalysts of mixed metal oxides were prepared by mixing a phase-pure M1 MoVNbTeOx with anatase-phase TiO2. Two methods were used to prepare the composite catalysts (the simple physically mixed or sol-gel method) for the improvement of the catalytic performance in the oxidative dehydrogenation of ethane (ODHE) process. The results showed that TiO2 particles with a smaller particle size were well dispersed on the M1 surface for the sol-gel method, which presented an excellent activity for ODHE. At the same operating condition (i.e., the contact time of 7.55 gcat·h/molC2H6 and the reaction temperature of 400 °C), the M1-TiO2-SM and M1-TiO2-PM achieved the space time yields of 0.67 and 0.52 kgC2H4/kgcat/h, respectively, which were about ~76% and ~35% more than that of M1 catalyst (0.38 kgC2H4/kgcat/h), respectively. The BET, ICP, XRD, TEM, SEM, H2-TPR, C2H6-TPSR, and XPS techniques were applied to characterize the catalysts. It was noted that the introduction of TiO2 raised the V5+ abundance on the catalyst surface as well as the reactivity of active oxygen species, which made contribution to the promotion of the catalytic performance. The surface morphology and crystal structure of used catalysts of either M1-TiO2-SM or M1-TiO2-PM remained stable as each fresh catalyst after 24 h time-on-stream tests.

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