Improved Photocatalytic Activity of La3+-Doped Bi2O3

2011 ◽  
Vol 239-242 ◽  
pp. 86-89 ◽  
Author(s):  
Jun Zeng ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Shao Hua Wang ◽  
Wei Hu
Keyword(s):  
Photocatalytic Activity ◽  
Binding Energy ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Diffuse Reflectance ◽  
Bet Surface Area

In this paper, Bi2O3 doped with different amount of La3+ was prepared. The prepared photocatalysts were characterized by BET, XRD, UV-VIS diffuse reflectance and XPS. The results show that 3%La3+-Bi2O3 prepared has the highest BET surface area, pore volume, the smallest pore size. 3%La3+-Bi2O3 exhibits the best photocatalytic activity. The results of further experiments show that the specific surface area, UV-Vis diffuse reflectance and the binding energy all play an important role in promotion of photocatalytic activity of Bi2O3 nanostructure.

Photocatalytic Activity of Bi2O3 Prepared by Different Precipitants

2011 ◽  
Vol 239-242 ◽  
pp. 998-1001 ◽  
Author(s):  
Jun Bo Zhong ◽  
Jun Zeng ◽  
Jian Zhang Li ◽  
Wei Hu
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Pore Volume ◽  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
Strong Dependence ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Average Size

Paralled flaw precipitation method has been employed to synthesize nanostructured Bi2O3. It is found that the bandgap and photocatalytic performance of Bi2O3 has a strong dependence on the kind of precipitants. The prepared photocatalysts were characterized by BET, XRD, UV-Vis diffuse reflectance and SEM. The results show that Bi2O3 prepared by NH3·H2O has the highest BET surface area, pore volume, the smallest pore size and the particle average size. Bi2O3 prepared by NH3·H2O exhibits the best photocatalytic activity. The results of further experiments show that bandgap and the specific surface area all play an important role in promotion of photocatalytic activity of Bi2O3 prepared by NH3·H2O.

The relationship between geotechnical index properties and the pore-size distribution of compacted clayey silts

2015 ◽  
Vol 22 (6) ◽  
Author(s):  
Nazile Ural
Keyword(s):  
Specific Surface ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Correlation Coefficients ◽  
Liquid Limit ◽  
Index Properties

AbstractIn this study, the relationships between geotechnical index properties and the pore-size distribution of compacted natural silt and artificial soil mixtures, namely, silt with two different clays and three different clay percentages (10%, 20%, and 40%), were examined and compared. Atterberg’s limit tests, standard compaction tests, mercury intrusion porosimetry, X-ray diffraction, scanning electron microscopy (SEM) analysis, and Brunauer-Emmett-Teller specific surface analysis were conducted. The results show that the liquid limit, the cumulative pore volume, and specific surface area of artificially mixed soils increase with an increase in the percentage of clay. The cumulative pore volume and specific surface area with geotechnical index properties were compared. High correlation coefficients were observed between the specific areas and both the liquid limit and the plasticity index, as well as between the cumulative pore volume and both the clay percentage and the

The Influence of Sinterng Temperature on the Phase, Microstructure and Textual Properties of Hollow Hydroxyapatite Microspheres

2011 ◽  
Vol 239-242 ◽  
pp. 2274-2279 ◽  
Author(s):  
Ying Chun Wang ◽  
Wen Hai Huang ◽  
Ai Hua Yao ◽  
De Ping Wang
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Sintering Temperature ◽  
Total Pore Volume ◽  
Precipitation Method ◽  
Simple Method ◽  
Air Atmosphere

A simple method to prepare hollow hydroxyapatite (HAP) microspheres with mespores on the surfaces is performed using a precipitation method assisted with Li2O-CaO-B2O3(LCB) glass fabrication process. This research is concerned with the effect of sintering temperature on the microstructure evolution, phase purity, surface morphology, specific surface area, and porosity after sintering process. The microspheres were sintered in air atmosphere at temperatures ranging from 500 to 900 °C. The starting hollow HAP microspheres and the sintered specimens were characterized by scanning electron microscope, X-ray diffractometer, specific surface area analyzer, and Hg porosimetry, respectively. The as-prepared microspheres consisted of calcium deficient hydroxyapatite. The results showed that the as-prepared hollow HAP microspheres had the highest specific surface areas, and the biggest total pore volume. The pore size distribution of the as-prepared hollow HAP microspheres were mainly the mesopores in the range of 2～40 nm. The specific surface area and total pore volume of hollow HAP microspheres decreased with increasing sintering temperature. Whereas the mean pore size increased with increasing sintering temperature. It showed that at 700°C, Ca-dHAP decomposes into a biphasic mixture of HAP and β-calcium phosphate(TCP).

scholarly journals Effects of the Pyrolysis Temperature on Adsorption of Carbamazepine and Ibuprofen by NaOH Pre-treated Pine Sawdust Biochars

2020 ◽  
Vol 42 (2) ◽  
pp. 29-39
Author(s):  
Jinwoo Kwak ◽  
Sangwoo Park ◽  
Jaegwan Shin ◽  
Kangmin Chon
Keyword(s):  
Ionic Strength ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pyrolysis Temperature ◽  
Repulsive Interaction ◽  
Pine Sawdust ◽  
Adsorption Mechanisms

Objective: The main purpose of this study was to examine the impacts of the pyrolysis temperature on the removal of pharmaceuticals (i.e., ibuprofen (IBF) and carbamazepine (CBZ)) using NaOH pre-treated biochars produced from pine sawdusts.Methods:Two different types of kinetic and isotherm models were applied to investigate the adsorption mechanisms of IBF and CBZ by the NaOH pre-treated biochars produced at 600℃ (PB-600) and 800℃ (PB-800). In addition, the removal efficiencies of IBF and CBZ by PB-600 and PB-800 were compared under various conditions (adsorbent doses: 5-40 mg/L; 20-160 mg/L; temperature: 15-45℃; ionic strength: 0-0.5 M) to assess their feasibility as an alternative adsorbent for the removal of pharmaceuticals. Results and Discussion:PB-800 could more effectively remove CBZ and IBF than PB-600 because of its larger specific surface area (PB-600 = 408.70 m<sup>2</sup>/g; PB-800 = 472.92 m<sup>2</sup>/g), pore volume (PB-600 = 0.336 cm<sup>3</sup>/g; PB-800 = 0.658 cm<sup>3</sup>/g), and pore size (PB-600 = 4.63 nm; PB-800 = 6.25 nm). The Langmuir isotherm was more suitable for adsorption of IBF by PB-600 and the Freundlich isotherm was well fitted to the adsorption of CBZ by PB-600 and adsorption of CBZ and IBF by PB-800. The adsorption of CBZ by PB-600 and PB-800 was not affected by temperature while the removal efficiency of IBF was decreased with increasing the temperature due to the increased repulsive interaction between IBF and the biochars. Furthermore, the effects of the ionic strength on the adsorption of IBF were more pronounced than that of CBZ due to the differences in the surface charge properties.Conclusions:The higher pyrolysis temperature can improve the physicochemical properties of the NaOH pre-treated pine sawdust biochars associated with the removal of the pharmaceuticals (i.e., CBZ and IBF). Moreover, the adsorption mechanisms of CBZ and IBF by the biochars were strongly influenced by their specific surface area, pore volume and pore size.

New Insight Technique for Synthesis of Silica Gel from Rice Husk Ash by Using Microwave Radiation

2014 ◽  
Vol 1025-1026 ◽  
pp. 574-579 ◽  
Author(s):  
Nuchanaporn Pijarn ◽  
Pichit Galajak
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Silica Gel ◽  
Specific Surface Area ◽  
Rice Husk ◽  
Pore Volume ◽  
Rice Husk Ash ◽  
Sol Gel ◽  
Microwave Technique

Silica gel is the chemical substance that has many good advantages such as absorbed moisture, porosity, small diameter, high surface area, and lightweight. It was synthesized by using rice husk ash via sol – gel heating in the microwave technique. The objectives in this work compose of synthesis silica gel by using the microwave technique before characterizatization. This raw material was archived from rice husk ash, obtained from agricultural waste. The silica gel, synthesized by conventional method (CVM) and commercial silica gel (COM), was also studied for comparison purposes. The results showed that successfully synthesized the silica gel by sol - gel technique using microwave. The XRD pattern of silica gel enhanced from this method was not sinificantly different as compared with CVM and COM methods. And the physical properties of this technique could be debated. The particle size of silca gel was determined by zetasizer and it was approxmately 50-70 nm. The pore size diameter, pore volume, and specific surface area of silica gel were calculated by Flowsorb II and a Quantachrome Autosorp-1. The pore size diameter, pore volume, and specific surface area of silica gel are 10-30 nm, 0.7-1.0 cm3/g, and 400-700 m2/g, respectively. Consequently, this work is considered to be the waste to make useful, and a great way to save energy and time in the silica gel synthesis.

scholarly journals Evaluation of coal and shale reservoir in Permian coal-bearing strata for development potential: A case study from well LC-1# in the northern Guizhou, China

2018 ◽  
Vol 37 (1) ◽  
pp. 194-218 ◽  
Author(s):  
Hongjie Xu ◽  
Shuxun Sang ◽  
Jingfen Yang ◽  
Jun Jin ◽  
Huihu Liu ◽  
...  
Keyword(s):  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Shale Gas ◽  
Pore Volume ◽  
Coalbed Methane ◽  
Total Pore Volume ◽  
Gas Content ◽  
Bet Specific Surface Area

Indentifying reservoir characteristics of coals and their associated shales is very important in understanding the co-exploration and co-production potential of unconventional gases in Guizhou, China. Accordingly, comprehensive experimental results of 12 core samples from well LC-1# in the northern Guizhou were used and analyzed in this paper to better understand their vertical reservoir study. Coal and coal measured shale, in Longtan Formation, are rich in organic matter, with postmature stage of approximately 3.5% and shales of type III kerogen with dry gas generation. All-scale pore size analysis indicates that the pore size distribution of coal and shale pores is mainly less than 20 nm and 100 nm, respectively. Pore volume and area of coal samples influenced total gas content as well as desorbed gas and lost gas content. Obvious relationships were observed between residual gas and BET specific surface area and BJH total pore volume (determined by nitrogen adsorption). For shale, it is especially clear that the desorbed gas content is negatively correlated with BET specific surface area, BJH total pore volume and clay minerals. However, the relationships between desorbed gas and TOC (total organic carbon) as well as siderite are all well positive. The coals and shales were shown to have similar anoxic conditions with terrestrial organic input, which is beneficial to development of potential source rocks for gas. However, it may be better to use a low gas potential assessment for shales in coal-bearing formation because of their low S1+S2 values and high thermal evolution. Nevertheless, the coalbed methane content is at least 10 times greater than the shale gas content with low desorbed gases, indicating that the main development unconventional natural gas should be coalbed methane, or mainly coalbed methane with supplemented shale gas.

Nanostructured BN–TiO2 composite with ultra-high photocatalytic activity

2017 ◽  
Vol 41 (20) ◽  
pp. 11640-11646 ◽  
Author(s):  
Bikramjeet Singh ◽  
Gurpreet kaur ◽  
Paviter Singh ◽  
Kulwinder Singh ◽  
Jeewan Sharma ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Boron Nitride ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Titanium Oxide ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
High Photocatalytic Activity ◽  
Large Pore Size

Boron nitride and titanium oxide composite (BN–TiO2) photocatalyst endowed with high specific surface area and large pore size was synthesized by ice bath method.

Modification of Pellet Materials by Low Temperature Plasma

2010 ◽  
Vol 97-101 ◽  
pp. 2369-2372
Author(s):  
Yong Jun Wang ◽  
Zhen Qing Wang ◽  
Li Nan Zhu
Keyword(s):  
Low Temperature ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Low Temperature Plasma ◽  
Activated Alumina ◽  
Temperature Plasma ◽  
Pellet Surface

Low temperature plasma made some modifications of pellet materials (activated alumina and haydite) placed between electrodes. It altered the characteristics of pellets after discharge, such as the pellet surface element proportion, binding energy, specific surface area, pore volume and pore size. The activated alumina surface parameters of specific surface area, pore volume and pore size increased after discharge, which was good for catalytic activity. The original pores on haydite surface were destroyed, and bigger holes were formed. Activated alumina would be polarized when placed between discharge electrodes, which enhanced the electric field intensity. Due to the effect of plasma, the solid pellet surface was modified, which was useful for pellet catalysis in application.

Photocatalytic Performance of SnO2 Prepared by Different Precipitants

2013 ◽  
Vol 331 ◽  
pp. 540-543
Author(s):  
Sheng Tian Huang ◽  
Jun Bo Zhong ◽  
Jian Zhang Li ◽  
Wei Hu
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
Strong Dependence ◽  
Bet Surface Area ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Average Size

Parallel flow precipitation has been employed to prepare nanostructured SnO2. It is found that the specific surface areas and photocatalytic performance of SnO2 has a strong dependence on the kind of precipitant. The prepared photocatalysts were characterized by BET, XRD, UV-Vis diffuse reflectance and SEM. The results show that SnO2 prepared by NH3·H2O + (NH4)2CO3 has the highest BET surface area and the smallest crystal average size. SnO2 prepared by NH3·H2O + (NH4)2CO3 exhibits the best photocatalytic activity. The results of further experiments show that the specific surface area plays an important role in promotion of photocatalytic activity of SnO2 prepared by NH3·H2O + (NH4)2CO3.

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