scholarly journals Photocatalytic Performance of Carbon Monolith/TiO2Composite

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Marina Maletić ◽  
Marija Vukčević ◽  
Ana Kalijadis ◽  
Zoran Laušević ◽  
Mila Laušević
Keyword(s):  
Photocatalytic Activity ◽  
Thermal Treatment ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Dip Coating ◽  
Surface Oxygen ◽  
Surface Oxygen Groups ◽  
Carbon Monolith ◽  
Oxygen Groups

The new and simple approach for deposition of catalytically active TiO2coating on carbon monolith (CM) carrier was presented. CM photocatalysts were impregnated with TiO2using titanium solution and thermal treatment, and their photocatalytic activity was investigated in the process of methylene blue (MB) photodegradation. For the purpose of comparison, CM composite photocatalysts were prepared by dip-coating method, which implies binder usage. The presence of TiO2on CM carrier was confirmed by Raman spectroscopy and scanning electron microscopy. The sorption characteristics of CM and the role of adsorption in the overall process of MB removal were evaluated through amount of surface oxygen groups obtained by temperature-programmed desorption and specific surface area determined by BET method. CM has shown good adsorption properties toward MB due to high amount of surface oxygen groups and relatively high specific surface area. It was concluded that photocatalytic activity increases with CM disc thickness due to increase of MB adsorption and amount of deposited TiO2. Good photocatalytic activity achieved for samples obtained by thermal treatment is the result of better accessibility of MB solution to the TiO2particles induced by binder absence.

scholarly journals Characterization of surface oxygen groups on different carbon materials by the Boehm method and temperature programmed desorption

2011 ◽  
Vol 76 (5) ◽  
pp. 757-768 ◽  
Author(s):  
Ana Kalijadis ◽  
Marija Vukcevic ◽  
Zoran Jovanovic ◽  
Zoran Lausevic ◽  
Mila Lausevic
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Materials ◽  
Temperature Programmed Desorption ◽  
Surface Oxygen ◽  
Surface Oxygen Groups ◽  
Bet Analysis ◽  
Temperature Programmed ◽  
Oxygen Groups

The surface characteristics of different carbon materials: activated carbon, carbon felt, glassy carbon and a porous carbon monolith were investigated. The specific surface area was examined by the BET method with N2 adsorption, the amount and the type of surface oxygen groups by Boehm titration as well as by temperature-programmed desorption (TPD). By comparing the results obtained using BET analysis with those of TPD and the Boehm method, it was found that the number of surface groups was not proportional to the specific surface area. The total amount of oxygen groups, obtained by TPD, is higher than the amount obtained by Boehm?s method for porous samples. The inconsistencies between these results originate from the fact that the Boehm method is limited to the determination of acidic and basic groups, whereas TPD provides information on the total number of all surface oxygen groups. In addition, the presence of porosity could reduce the solvent-accessible surface in the Boehm method. The TPD profiles of CO evolution showed the presence of a low temperature maximum, below 650 K, which originates from CO2 reduction on the carbon material surface.

scholarly journals Influence of boron doping on characteristics of glucose based hydrothermal carbons

2022 ◽  
pp. 1-1
Author(s):  
Ana Kalijadis ◽  
Marina Maletic ◽  
Andjelika Bjelajac ◽  
Biljana Babic ◽  
Tamara Minovic-Arsic ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Boron Content ◽  
Structural Parameters ◽  
Surface Characteristics ◽  
Boron Doping ◽  
Surface Oxygen Groups ◽  
Boron Doped ◽  
Oxygen Groups

In this study, the influence of boron doping on structural and surface properties of carbon material synthesized by hydrothermal method was investigated, and the obtained results were compared with the previously published influence that boron has on characteristics of carbonized boron-doped hydrothermal carbons (CHTCB). Hydrothermal carbons doped with boron (HTCB), were obtained by hydrothermal synthesis of glucose solution with the different nominal concentrations of boric acid. It was found that glucose based hydrothermal carbon does not have developed porosity, and the presence of boron in their structure has insignificant influence on it. On the contrary, additional carbonization increases the specific surface area of the undoped sample, while the increase in boron content drastically decreases specific surface area. Boron doping leads to a decrease in the amount of surface oxygen groups, for both, hydrothermally synthesized and additionally carbonized material. Raman analysis showed that boron content does not affect the structural arrangement of HTCB samples, and Raman structural parameters show higher degree of disorder, compared to the CHTCB samples. Comparison of structural and surface characteristics of hydrothermal carbons and carbonized materials contributes to the study of the so far, insufficiently clarified influence that boron incorporation has on the material characteristics.

Facile synthesis of novel Roe-like TiO2 hollow nanospheres with mesoporous cavity for improved photocatalytic activity

2017 ◽  
Vol 10 (03) ◽  
pp. 1750028 ◽  
Author(s):  
Yan Zhu ◽  
Xiaoxia Yan ◽  
Yuanxin Ge ◽  
Shumin Wang ◽  
Dongmei Deng ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Self Assembly ◽  
Charge Separation ◽  
Synergistic Effects ◽  
Assembly Process ◽  
Hollow Nanospheres ◽  
Facile Synthesis

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.

Bi2WO6 Nanoparticles Prepared by Combustion Synthesis with Different Fuels and their Photocatalytic Activity

2014 ◽  
Vol 604 ◽  
pp. 93-101
Author(s):  
Maris Kodols ◽  
Sabine Didrihsone ◽  
Janis Grabis
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Citric Acid ◽  
Ethylene Glycol ◽  
Specific Surface ◽  
Crystallite Size ◽  
Combustion Synthesis ◽  
Surface Area ◽  
Specific Surface Area ◽  
Solution Ph

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.

Effect of Anatase/Rutile Phase Ratio on the Photodegradation of Methylene Blue under UV Irradiation

2020 ◽  
Vol 998 ◽  
pp. 78-83
Author(s):  
Yi Yi Zaw ◽  
Du Ang Dao Channei ◽  
Thotsaphon Threrujirapapong ◽  
Wilawan Khanitchaidecha ◽  
Auppatham Nakaruk
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Band Gap ◽  
Surface Area ◽  
Calcination Temperature ◽  
Organic Compounds ◽  
Specific Surface Area ◽  
Uv Irradiation ◽  
Rutile Phase

Titanium dioxide (TiO2) is known as one of the widely used catalysts in photocatalysis process. Recently, the photocatalysis of TiO2 has been implied in water purification and treatment, particularly dyes and organic compounds degradations. Naturally, the TiO2 can be found in three phases including anatase, rutile and brookite; each phase has its own specific properties such as grain size, stability and band gap energy. In this work, the effect of calcination temperature on the structure, morphology and photocatalytic activity were investigated. The data suggested that the anatase/rutile ratio of TiO2 can be controlled through the calcination process. The phase transformation data strongly indicated the liner function between percentage of rutile phase and calcination temperature. The BET analysis provided the consistent data with XRD patterns by showing that the specific surface area was decreased by increasing calcination temperature. The photodegradation of methylene blue under UV irradiation proved that the mixed phase of anatase/rutile ratio at 78.5/21.5 provided the highest photocatalytic activity. The phase composition ratio can influence the nanoparticles properties including band gap, specific surface area and energy band structure. Therefore, the control of anatase/rutile ratio was an alternative to enhance the photocatalytic activity of TiO2 nanoparticles for dyes and organic compounds degradations.

Synthesis and Photocatalytic Property of BiVO4/FeVO4 Composite Novel Photocatalyst

2010 ◽  
Vol 129-131 ◽  
pp. 784-788 ◽  
Author(s):  
Min Wang ◽  
Qiong Liu ◽  
Dong Zhang
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photocatalytic Property ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Triclinic Phase ◽  
Xrd Patterns

BiVO4/FeVO4 composite photocatalyst samples were prepared by calcining the mixture of FeVO4 and BiVO4 precusor which were prepared through liquid phase precipitation method for further increasing the photocatalytic efficiency of FeVO4. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microsoope（SEM）and specific surface area (BET). The photocatalytic activity was evaluated by photocatalytic degradation of methyl orange (MO) solution under visible light. The XRD patterns indicate that BiVO4/FeVO4 composite photocatalysts consist of triclinic phase and the lattice was not distorted beacause of doping Bi. But the morphology change greatly and the specific surface area has little change. In the experimental conditions used, the optimal photocatalytic activity for all the prepared samples was reached when BiVO4 doping was 22 at%. The degradation rate of MO was increased by 20％ or so than that of pure FeVO4.

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