The Hydrothermal Synthesis and Photocatalysis of TiO2 Powders

2011 ◽  
Vol 183-185 ◽  
pp. 2024-2027
Author(s):  
Li Ming Jiang

Titania powders were prepared under hydrothermal conditions by employing organic molecule β-cyclodextrin(CD) as template, and characterized by means of TGA、XRD、BET . The effects of the pH on the specific surface area and photocatalytic performance of titania were discussed. The results showed that titania powders were anatase structure;the titania powders with specific surface area up to 216.2 m2g-1 were prepared while the system pH was about 1 , and the powders had the best photocatalytic activity.

2020 ◽  
Vol 13 (07) ◽  
pp. 2051037
Author(s):  
Ke Han ◽  
Guobao Li ◽  
Fang Li ◽  
Mingming Yao

For the sake of improving the photocatalytic performance of TiO2, we prepared the B/Ag/Fe tridoped TiO2 films on common glass and stone substrates by the sol–gel method. In this work, the optical absorption, recombination of photogenerated electrons (e−) and holes (h[Formula: see text]), crystal types, thermal stability, composition, specific surface area and photocatalytic activity of the modified TiO2 films were investigated. The results indicated that B/Ag/Fe tridoping not only enhanced the absorption of visible light by TiO2, but inhibited the recombination of electron–hole (e−/h[Formula: see text]) pairs. The tridoping also promoted the formation of anatase and prevented the transformation of anatase to rutile at high temperature. The composite TiO2 has a large specific surface area, about three times that of pure TiO2. The photocatalytic activity of the TiO2 films were evaluated by methyl green (MG) and formaldehyde degradation. In all samples, the B/Ag/Fe tridoped TiO2 film exhibited the highest degradation rate of MG under both ultraviolet and visible light irradiation. The improvement of photocatalytic performance of TiO2 films is due to the synergistic effect of the B/Ag/Fe tridoping, which enhances the absorption of visible light and prolongs the lifetime of e−/h[Formula: see text] pairs and facilitates transfer of interface charge.


RSC Advances ◽  
2017 ◽  
Vol 7 (57) ◽  
pp. 36101-36111 ◽  
Author(s):  
Haiyan Ji ◽  
Yamin Fan ◽  
Jia Yan ◽  
Yuanguo Xu ◽  
Xiaojie She ◽  
...  

2D/2D SnO2/GL-C3N4 photocatalysts with large specific surface area and high coupling heterointerface extent were synthesized by an environmental friendly hydrothermal method, showing excellent photocatalytic performance on RhB degradation.


2021 ◽  
Author(s):  
Pengxi Li ◽  
Jiepeng Wang ◽  
Liming Li ◽  
Shili Song ◽  
Xianming Yuan ◽  
...  

ZnMoO4 with oxygen vacancy (ZnMoO4-OV) porous nanosheet was synthesized by hydrothermal synthesis and hydrogenation reduction method. The ZnMoO4-OV porous nan sheet delivers a higher specific surface area together with a...


2007 ◽  
Vol 336-338 ◽  
pp. 2017-2020 ◽  
Author(s):  
Fan Yong Ran ◽  
Wen Bin Cao ◽  
Yan Hong Li ◽  
Xiao Ning Zhang

Nanosize anatase TiO2 powders have been synthesized by hydrothermal synthesis by using technical grade TiOSO4 as precursor and urea as precipitating agent. The initial pressure of the reaction system was set at 6 MPa. Stirring speed was fixed at 300r/min. The reaction system reacted at the temperature ranged from 110 to 150°C for holding 2hrs to 8hrs and the concentration of the precursor was ranged from 0.25M to1.5M. XRD patterns show that the synthesized powders are in the form of anatase phase. Calculated grain size is ranged from 6.7 to 8.9nm by Scherrer method from the line broadening of the (101) diffraction peak of anatase. The specific surface area of the powders synthesized under different conditions is ranged from 124 to 240m2/g. The grain size of the powders increases with the increase of the reaction temperature, holding time and precursor concentration, respectively. The specific surface area decreases with the increase of reaction temperature and holding time, and does not obviously change with the change of precursor concentration when the concentration of the precursor is less than 1M. However, when the concentration is higher than 1M, the specific surface area will decrease quickly with the increase of the precursor concentration. XRD and DSC-TG analysis shows that the synthesized anatase TiO2 will begin to transform to rutile TiO2 at about 840°C. When heated to 1000°C for holding 1h, the anatase powders will transform to rutile completely.


2021 ◽  
Vol 21 (12) ◽  
pp. 5835-5845
Author(s):  
Ranjith Balu ◽  
Arivuoli Dakshanamoorthy

Supercapacitor with high specific capacity is desirable for various energy storage and high powerdensity applications. Though Graphene has been the preferred material for high current density, nanocomposites have been attempted to increase the specific capacitance. Hydrothermal synthesis of cadmium sulfide/graphene (CdS/G) nanocomposite with CdS nanoparticles anchored/decorated over the graphene sheets is reported. The structural studies reveal the hexagonal phase of the prepared materials. The specific surface area (BET) and porosity is found to increase upon nanocomposite formation. The electrochemical characteristics such as cyclic voltammetry (CV), GCD and EIS of the CdS/G nanocomposite have been investigated. The capacitance of CdS/G nanocomposite almost doubled to 248 Fg−1 indicating the enhanced performance of the nanocomposite system and in addition it also showed excellent cycling stability of 74.8 percent after 1000 cycles. The supercapacitor investigated retained the initial energy density after charge-discharge, at 0.5 A/g for 1000 cycles. The graphene nanosheets increased the specific surface area and interfacial electron transfer of the composite material. It enhances the specific capacitance and cyclic stability of the supercapacitor device.


2017 ◽  
Vol 10 (03) ◽  
pp. 1750028 ◽  
Author(s):  
Yan Zhu ◽  
Xiaoxia Yan ◽  
Yuanxin Ge ◽  
Shumin Wang ◽  
Dongmei Deng ◽  
...  

A facile approach was developed to synthesize novel Roe-like TiO2 hollow nanospheres via a template-assisted self-assembly process. These TiO2 nanospheres possessing mesoporous cavity manifest significantly improved photocatalytic activity owing to the synergistic effects of increased charge separation, more efficient use of the light and specific surface area.


2014 ◽  
Vol 604 ◽  
pp. 93-101
Author(s):  
Maris Kodols ◽  
Sabine Didrihsone ◽  
Janis Grabis

The influence of glycine, glycerine, ethylene glycol and citric acid fuel and their ratio to NO3- on formation and dispersity of Bi2WO6 nanoparticles prepared by combustion synthesis has been studied. The pure crystalline Bi2WO6 with specific surface area 24,8 m2/g and crystallite size of 28 nm was obtained by using glycerine as fuel at its ratio to NO3- of 0,67. The photocatalytic activity of the prepared Bi2WO6 in degradation of methylene blue depended on its specific surface area of samples and solution pH.


2019 ◽  
Vol 43 (3) ◽  
pp. 1230-1237 ◽  
Author(s):  
Mingcai Yin ◽  
Wenli Zhang ◽  
Hui Li ◽  
Chaojun Wu ◽  
Fangfang Jia ◽  
...  

The specific surface area and composition are found to be the key factors influencing the photocatalytic performance of MoS2+x.


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