Modifying the Silver–Titania Nanocomposites with Carbonaceous Materials to Remove the Pollutants from Domestic Waste Water

2021 ◽  
Vol 21 (4) ◽  
pp. 2278-2291
Author(s):  
Anca Peter ◽  
Leonard Mihaly Cozmuta ◽  
Camelia Nicula ◽  
Anca Mihaly Cozmuta ◽  
Catalina Mihaela Talasman ◽  
...  
Keyword(s):  
Waste Water ◽  
Photocatalytic Activity ◽  
Salicylic Acid ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Domestic Wastewater ◽  
Nitrogen Adsorption ◽  
Domestic Waste ◽  
Adsorption Desorption

The aim of this study was to prepare and characterize nanostructured composites based of TiO2, carbonaceus materials (GN or GO) and Ag and the test their capacity to remove the pollutants from domestic wastewater. The composites were characterized by IR and UV-Vis spectroscopy, X-ray diffraction, electron microscopy and nitrogen adsorption–desorption measurements. The photocatalytic activity was measured from the experiment of salicylic acid (SA) degradation. The capacity to remove the pollutants from domestic wastewater was performed by considering the absorbance of residual solution at 200 nm. The non-calcined composites have high specific surface area (˜300 m2/g), but nitrogen adsorption–desorption isotherms showed a porous structure with closed pores. The porosity of the thermal treated composites is about 10 times less, but the pores are open. The salicylic acid was 94% degraded over all composites, showing their efficient photoactivity. A percent of 70% of pollutants were removed over the calcined composites with GN and ˜67% on those with GO. It was no statistically significant difference between the photocatalytical efficiency of GN- and GO-based composites. Even if the calcined composites have the specific surface area about 10 times lower, their lower gap energy, higher degree of crystallinity and photocatalytic activity make them efficient candidates for removal of pollutants from domestic waste water. The photodegradation mechanism occurred mostly by π–π interactions between GN/GO and pollutant molecules.

Synthesis of Novel Core-Shell Structured Hydroxyapatite/Meso-Silica for Removal of Methylene Blue from Aqueous Solutions

2012 ◽  
Vol 463-464 ◽  
pp. 543-547 ◽  
Author(s):  
Cheng Feng Li ◽  
Xiao Lu Ge ◽  
Shu Guang Liu ◽  
Fei Yu Liu
Keyword(s):  
Methylene Blue ◽  
Aqueous Solutions ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Low Cost ◽  
Nitrogen Adsorption ◽  
Precipitation Method ◽  
Core Shell ◽  
Adsorption Desorption

Core-shell structured hydroxyapatite (HA)/meso-silica was prepared and used as absorbance of methylene blue (MB). HA/meso-silica was synthesized in three steps: preparation of nano-sized HA by wet precipitation method, coating of dense silica and deposition of meso-silica shell on HA. As-received samples were characterized by Fourier transformed infare spectra, small angle X-ray diffraction, nitrogen adsorption-desorption isotherm and transmission electron microscopy. A wormhole framework mesostructure was found for HA/meso-silica. The specific surface area and pore volume were 128 m2•g-1 and 0.36 cm3•g-1, respectively. From the adsorption isotherm, HA/meso-silica with the great specific surface area exhibited a prominent adsorption capacity of MB (134.0 mg/g) in comparison with bare HA (0 mg/g). This study might shed light on surface modification of conventional low-cost adsorbents for removal of organic pollutants from aqueous solutions.

Effects of Carbonation on the Specific Surface BET of Cement Mortar Measured by Two Different Methods: Nitrogen Adsorption and Water Adsorption

2014 ◽  
Vol 931-932 ◽  
pp. 421-425 ◽  
Author(s):  
Son Tung Pham ◽  
William Prince
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Water Adsorption ◽  
Cement Mortar ◽  
Nitrogen Adsorption ◽  
Accelerated Carbonation ◽  
Molecular Sizes ◽  
The Difference ◽  
Adsorption Desorption

The objective of this work was to examine the microstructural changes caused by the carbonation of normal mortar. Samples were prepared and subjected to accelerated carbonation at 20°C, 65% relative humidity and 20% CO2concentration. The evolutions of the pore size distribution and the specific surface area during carbonation were calculated from the adsorption - desorption isotherms of water vapour and nitrogen. Conflicts observed in the results showed that the porous domains explored by these two methods are not the same due to the difference in molecular sizes of nitrogen and water. These two techniques therefore help to complementarily evaluate the effects of carbonation. The study also helped to explain why results in the literature diverge greatly on the influence of carbonation on specific surface area.

Sol-gel Synthesis of a Novel χSm2Ti2O7/HZSM-5 Composite Photocatalyst for the Promoted Activity on RBR X-3B Degradation

2017 ◽  
Vol 14 (1) ◽  
pp. 17-25
Author(s):  
Wenjie Zhang ◽  
Jiao Yang ◽  
Ling Du
Keyword(s):  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Bandgap Energy ◽  
Powder Materials ◽  
Sol Gel Synthesis ◽  
Adsorption Desorption

Background: Pyrochloro structured Sm2Ti2O7 has photocatalytic activity on degradation of organic substances and on hydrogen evolution from water. Powder materials usually encounter the obstacle of separating from treated water. HZSM-5 zeolite is a kind of porous structured material with large surface area. Its role as a support for Sm2Ti2O7 is interesting. Methods: The supported Sm2Ti2O7 was synthesized using sol-gel method. The composite χSm2Ti2O7/HZSM-5 was characterized by XRD, SEM, TEM, FT-IR/FIR, UV-Vis DRS, N2 adsorption- desorption and XPS measurements. Photocatalytic degradation of Reactive Brilliant Red X-3B (RBR X-3B) was measured to evaluate the activity of the composite. Results: Sm2Ti2O7 is in the pyrochlore phase after loading on the surface of HZSM-5 zeolite. The crystal cell of pyrochlore Sm2Ti2O7 continuously expanses with decreasing Sm2Ti2O7 loading content in the composite. Bandgap energy of Sm2Ti2O7 is enlarged after supporting. The specific surface area of Sm2Ti2O7 was enlarged from 9.8 m2/g to 93 m2/g after loading. Both of the adsorption capacity and photocatalytic activity of the χSm2Ti2O7/HZSM-5 are greater than those of pure Sm2Ti2O7. After 120 min of irradiation, 73.1% of the initial RBR X-3B molecules are decomposed on 70%Sm2Ti2O7/HZSM-5, and only 27.7% of the dye is decomposed on the bare Sm2Ti2O7. Conclusion: Sm2Ti2O7 crystal growth is constrained after loading due to dispersion of Sm2Ti2O7 on the surface of HZSM-5. The specific surface area of Sm2Ti2O7 is significantly enlarged after loading. All the supported samples have greatly enhanced photocatalytic activity as compared to the bare Sm2Ti2O7.

scholarly journals Surface Structure Engineering of Nanosheet-Assembled NiFe2O4 Fluffy Flowers for Gas Sensing

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 297
Author(s):  
Xiaofeng Wang ◽  
Xu Li ◽  
Guozheng Zhang ◽  
Zihao Wang ◽  
Xue-Zhi Song ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Nitrogen Adsorption ◽  
X Ray ◽  
Adsorption Desorption ◽  
Sensing Performance

In this work, we present a strategy to improve the gas-sensing performance of NiFe2O4 via a controllable annealing Ni/Fe precursor to fluffy NiFe2O4 nanosheet flowers. X-ray diffraction (XRD), a scanning electron microscope (SEM), nitrogen adsorption–desorption measurements and X-ray photoelectron spectroscopy (XPS) were used to characterize the crystal structure, morphology, specific surface area and surface structure. The gas-sensing performance was tested and the results demonstrate that the response was strongly influenced by the specific surface area and surface structure. The resultant NiFe2O4 nanosheet flowers with a heating rate of 8 °C min−1, which have a fluffier morphology and more oxygen vacancies in the surface, exhibited enhanced response and shortened response time toward ethanol. The easy approach facilitates the mass production of gas sensors based on bimetallic ferrites with high sensing performance via controlling the morphology and surface structure.

scholarly journals Synthesis, Characterization, and Photocatalytic Activity of Zn-Doped SnO2/Zn2SnO4Coupled Nanocomposites

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Tiekun Jia ◽  
Junwei Zhao ◽  
Fang Fu ◽  
Zhao Deng ◽  
Weimin Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Synthesis Method ◽  
Diffuse Reflection Spectroscopy ◽  
Transmission Electron ◽  
20 Nm ◽  
Adsorption Desorption

Zn-doped SnO2/Zn2SnO4nanocomposites were prepared via a two-step hydrothermal synthesis method. The as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), UV-vis diffuse reflection spectroscopy, and adsorption-desorption isotherms. The results of FESEM and TEM showed that the as-prepared Zn-doped SnO2/Zn2SnO4nanocomposites are composed of numerous nanoparticles with the size ranging from 20 nm to 50 nm. The specific surface area of the as-prepared Zn-doped SnO2/Zn2SnO4nanocomposites is estimated to be 71.53 m2/g by the Brunauer-Emmett-Teller (BET) method. The photocatalytic activity was evaluated by the degradation of methylene blue (MB), and the resulting showed that Zn-doped SnO2/Zn2SnO4nanocomposites exhibited excellent photocatalytic activity due to their higher specific surface area and surface charge carrier transfer.

scholarly journals TEXTURAL AND MORPHOLOGICAL CHARACTERIZATION OF COPPER(II)-EXCHANGED ROMANIAN CALCIUM BENTONITE

2017 ◽  
Vol 20 (3) ◽  
Author(s):  
ANA-MARIA GEORGESCU ◽  
GHEORGHE BRABIE ◽  
ILEANA DENISA NISTOR ◽  
CLAUDE PENOT ◽  
FRANÇOISE NARDOU
Keyword(s):  
Ion Exchange ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Nitrogen Adsorption ◽  
Desorption Isotherm ◽  
Scanning Electron Micrographs ◽  
Adsorption Desorption ◽  
Calcium Bentonite ◽  
Scanning Electron

<p>Romanian calcium bentonite was modified by copper(II) ion-exchange, by varying the copper precursors (chloride, sulphate) and synthesis parameters (pH, temperature, time). The quantification of the Cu(II) ions was carried out by atomic absorption spectrophotometer. The modified bentonites were characterized by textural analysis (specific surface area by the Brunauer-Emmett-Teller method (BET) and by nitrogen adsorption/desorption isotherm), structural composition (X-ray diffraction (XRD)) and morphological analysis (scanning electron microscopy (SEM)). Analysis of the nitrogen adsorption/desorption isotherm shows that ion exchanged bentonites, not only contain mesopores, but micropores in larger quantities too. The values of the specific surface area increased by about 20 m<sup>2</sup>/g compared with raw bentonite, but the interlamellar distance values do not vary substantially. Scanning electron micrographs were acquired to demonstrate changes in the texture of the clay before and after ion exchange.</p>

Preparation and Characterization of Monolithic Al2O3 Aerogels

2016 ◽  
Vol 852 ◽  
pp. 591-595
Author(s):  
Heng Chen ◽  
Xue Ye Sui ◽  
Chang Ling Zhou ◽  
Chong Hai Wang ◽  
Fu Tian Liu
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Supercritical Drying ◽  
Aluminium Chloride ◽  
Porous Network ◽  
Drying Technology ◽  
Adsorption Desorption

Al2O3 aerogels were obtained through sol-gel process and ethanol supercritical drying technology using anhydrous aluminium chloride (AlCl3) and propylene oxide as precursor and gelation initiator respectively. Monolithic Al2O3 aerogels with porous and large specific surface area were achieved in our studies. Morphology and properties of Al2O3 aerogels were investigated by techniques of X-ray diffraction, Nitrogen adsorption/desorption analysis, Scanning electron microscopy, and Fourier transform infrared spectroscope. The results showed that the Al2O3 aerogels possessed a porous network microstructure made up of needles or rod-shaped particles and a specific surface area of 398 m2/g at 600°C. It was transformed to θ-Al2O3 after calcined at 1200°C.

scholarly journals Nanometer Pore Structure Characterization of Taiyuan Formation Shale in the Lin-Xing Area Based on Nitrogen Adsorption Experiments

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Chenlong Ding ◽  
Jinxian He ◽  
Hongchen Wu ◽  
Xiaoli Zhang
Keyword(s):  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Shale Gas ◽  
Pore Volume ◽  
Ordos Basin ◽  
Total Pore Volume ◽  
Nitrogen Adsorption ◽  
Taiyuan Formation

Ordos Basin is an important continental shale gas exploration site in China. The micropore structure of the shale reservoir is of great importance for shale gas evaluation. The Taiyuan Formation of the lower Permian is the main exploration interval for this area. To examine the nanometer pore structures in the Taiyuan Formation shale reservoirs in the Lin-Xing area, Northern Shaanxi, the microscopic pore structure characteristics were analyzed via nitrogen adsorption experiments. The pore structure parameters, such as specific surface area, pore volume, and aperture distribution, of shale were calculated; the significance of the pore structure for shale gas storage was analyzed; and the main controlling factors of pore development were assessed. The results indicated the surface area and hole volume of the shale sample to be 0.141–2.188 m2/g and 0.001398–0.008718 cm3/g, respectively. According to the IUPAC (International Union of Pure and Applied Chemistry) classification, mesopores and macropores were dominant in the pore structure, with the presence of a certain number of micropores. The adsorption curves were similar to the standard IV (a)-type isotherm line, and the hysteresis loop type was mainly similar to H3 and H4 types, indicating that most pores are dominated by open type pores, such as parallel plate-shaped pores and wedge-shaped slit pores. The micropores and mesopores provide the vast majority of the specific surface area, functioning as the main area for the adsorption of gas in the shale. The mesopores and macropores provide the vast majority of the pore volume, functioning as the main storage areas for the gas in the shale. Total organic carbon had no notable linear correlation with the total pore volume and the specific surface area. Vitrinite reflectance (Ro) had no notable correlation with the specific surface area, but did have a low “U” curve correlation with the total pore volume. There was no relationship between the quartz content and specific surface area and total pore volume. In addition, there was no notable correlation between the clay mineral content and total specific surface area and total pore volume.

Synthesis of High Quality Porous Carbon from Water Hyacinth

2020 ◽  
Vol 860 ◽  
pp. 173-177
Author(s):  
Otong Nurhilal ◽  
Renaldy Sharin Lesmana ◽  
Karina Ramadayanti ◽  
Sholihatul Habibah ◽  
Sahrul Hidayat ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Porous Carbon ◽  
Water Hyacinth ◽  
Invasive Plant ◽  
Proximate Analysis ◽  
High Quality ◽  
Porous Volume ◽  
Adsorption Desorption

Water Hyacinth (WH) is a plant that can absorb various pollutants in water. However, this plant is categorized as an invasive plant that can become a weed in the waters. To improve the functionality of WH, processing of WH is needed to be used for various applications. One of modifications of WH is as porous carbon for battery cathode composite. In this paper, we reported a synthesis of a porous carbon from WH. WH is processed into carbon by carbonization at various temperatures of 400, 500 and 600 °C with various activators of KOH, H3PO4 and ZnCl2 to obtain high quality porous carbon which has high electrical conductivity, large specific surface area and large porous volume. All synthesized carbons were characterized by proximate analysis measurements, scanning electron microscopy (SEM), and N2 adsorption-desorption measurements. The highest carbon fixed content of 37.79% is obtained from charcoal with a carbonization temperature of 400 °C. The largest specific surface area of 264.77 m2/g was obtained from activated carbon with H3PO4 as activator. The values of pore volume and pore radius were 0.186 cm3/g and 1.56 nm, respectively.

Sign in / Sign up

Export Citation Format

Share Document