Surface functional groups and defects on carbon nanotubes affect adsorption–desorption hysteresis of metal cations and oxoanions in water

2014 ◽  
Vol 1 (5) ◽  
pp. 488-495 ◽  
Author(s):  
Jie Li ◽  
Changlun Chen ◽  
Shouwei Zhang ◽  
Xiangke Wang
Keyword(s):  
Carbon Nanotubes ◽  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Metal Ion ◽  
Ion Adsorption ◽  
Surface Functional Groups ◽  
Metal Ion Adsorption ◽  
Desorption Hysteresis ◽  
Adsorption Desorption

This study probed the effects of functional groups, specific surface area and defects on metal ion adsorption and desorption.

scholarly journals Bio-polishing sludge adsorbents for dye removal

2016 ◽  
Vol 18 (4) ◽  
pp. 15-21 ◽  
Author(s):  
Muhammad Abbas Ahmad Zaini ◽  
Norulaina Alias ◽  
Mohd. Azizi Che Yunus
Keyword(s):  
Methylene Blue ◽  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
Treatment Strategies ◽  
Blue Dye ◽  
Surface Functional Groups ◽  
Adsorption Capacities ◽  
Maximum Removal

Abstract The objective of this work is to evaluate the removal of methylene blue dye by bio-polishing sludge-based adsorbents. The adsorbents were characterized according to the specific surface area, pH upon the treatment and surface functional groups. The adsorption of dye was carried out at room temperature, and the adsorption data were analyzed using the isotherm and kinetics models. The bio-polishing sludge is rich in ash content, and the presence of surface functional groups varied with the treatment strategies. The specific surface area of adsorbents is between 7.25 and 20.8 m2/g. Results show that the maximum removal of methylene blue by sludge adsorbents was observed to have the following order: untreated sludge (SR) > zinc chloride-treated (SZ) > microwave-dried (SW) = potassium carbonate-treated (SK) > acid-washed (SH). The maximum adsorption capacities for SR and SZ as predicted by the Langmuir model are 170 and 135 mg/g, respectively. Although SR demonstrates a higher maximum removal than SZ, the latter exhibits greater removal intensity and rate constant even at high dye concentration. The bio-polishing sludge is a promising adsorbent for dye wastewater treatment.

Study of Characteristic of Vetiver Fiber Before and after Alkaline Treatment

2010 ◽  
Vol 123-125 ◽  
pp. 1191-1194 ◽  
Author(s):  
Wimonlak Sutapun ◽  
Nitinat Suppakarn ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Thermogravimetric Analysis ◽  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Surface Analysis ◽  
Alkaline Treatment ◽  
X Ray Diffraction ◽  
Surface Functional Groups ◽  
X Ray ◽  
Before And After

In this study, untreated and alkali-treated vetiver fibers were characterized by thermogravimetric analysis, BET surface analysis, X-ray diffraction and FTIR (ATR) microspectroscopy,. It was revealed that the alkaline treatment influenced properties of vetiver fiber. By the treatment, some hemicellulose and lignin were removed, resulting in higher decomposition temperatures. In addition, the specific surface area were decreased, and crystalline structure was altered. However, no evidence of changes in surface functional groups was observed.

scholarly journals Development and Characterization of Composite Carbon Adsorbents with Photocatalytic Regeneration Ability: Application to Diclofenac Removal from Water

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 173
Author(s):  
Velma Beri Kimbi Yaah ◽  
Satu Ojala ◽  
Hamza Khallok ◽  
Tiina Laitinen ◽  
Marcin Selent ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
Palm Kernel ◽  
Hydrothermal Carbonization ◽  
Carbon Composite ◽  
Carbon Adsorbents ◽  
Regeneration Ability ◽  
Activation Temperature

This paper presents results related to the development of a carbon composite intended for water purification. The aim was to develop an adsorbent that could be regenerated using light leading to complete degradation of pollutants and avoiding the secondary pollution caused by regeneration. The composites were prepared by hydrothermal carbonization of palm kernel shells, TiO2, and W followed by activation at 400 °C under N2 flow. To evaluate the regeneration using light, photocatalytic experiments were carried out under UV-A, UV-B, and visible lights. The materials were thoroughly characterized, and their performance was evaluated for diclofenac removal. A maximum of 74% removal was observed with the composite containing TiO2, carbon, and W (HCP25W) under UV-B irradiation and non-adjusted pH (~5). Almost similar results were observed for the material that did not contain tungsten. The best results using visible light were achieved with HCP25W providing 24% removal of diclofenac, demonstrating the effect of W in the composite. Both the composites had significant amounts of oxygen-containing functional groups. The specific surface area of HCP25W was about 3 m2g−1, while for HCP25, it was 160 m2g−1. Increasing the specific surface area using a higher activation temperature (600 °C) adversely affected diclofenac removal due to the loss of the surface functional groups. Regeneration of the composite under UV-B light led to a complete recovery of the adsorption capacity. These results show that TiO2- and W-containing carbon composites are interesting materials for water treatment and they could be regenerated using photocatalysis.

scholarly journals Preparation, characterization and application of CS@PDA@Fe3O4 nanocomposite as a new magnetic nano-adsorber for the removal of metals and dyes in wastewater

RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23679-23685
Author(s):  
Xingjing Zhang ◽  
Baohe Li ◽  
Xiaoqian Han ◽  
Nong Wang
Keyword(s):  
Heavy Metal ◽  
Metal Ion ◽  
Heavy Metal Ion ◽  
Ion Adsorption ◽  
Metal Ion Adsorption

Synthesis of CS@PDA@Fe3O4 nanocomposite and heavy metal ion adsorption.

Functionalization and Tip-open of Carbon Nanotubes for High-Performance Symmetric Supercapacitor

2021 ◽  
Author(s):  
Yaxiong Zhang ◽  
Erqing Xie
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Specific Surface ◽  
Surface Area ◽  
Chemical Stability ◽  
High Aspect Ratio ◽  
High Performance ◽  
Large Specific Surface Area ◽  
Symmetric Supercapacitor

Carbon nanotubes (CNTs) have been widely studied as supercapacitor electrodes because of their excellent conductivity, high aspect ratio, excellent mechanical properties, chemical stability, and large specific surface area. However, the...

Study of the Porous Structure and High Adsorption Capacity of Biomass-Based Activated Carbon Prepared from Aspen Wood by Ferric Nitrate III Activation

2021 ◽  
Vol 15 (2) ◽  
pp. 131-144
Author(s):  
Chunjiang Jin ◽  
Huimin Chen ◽  
Luyuan Wang ◽  
Xingxing Cheng ◽  
Donghai An ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Specific Surface ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Mass Ratio ◽  
Aspen Wood ◽  
Surface Functional Groups ◽  
Wood Sawdust

In this study, aspen wood sawdust was used as the raw material, and Fe(NO3)3 and CO2 were used as activators. Activated carbon powder (ACP) was produced by the one-step physicochemical activation method in an open vacuum tube furnace. The effects of different mass ratios of Fe(NO3)3 and aspen wood sawdust on the pore structure of ACP were examined under single-variable experimental conditions. The mass ratio was 0–0.4. The detailed characteristics of ACP were examined by nitrogen adsorption, scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. The adsorption capacity of ACP was established by simulating volatile organic compounds (VOCs) using ethyl acetate. The results showed that ACP has a good nanostructure with a large pore volume, specific surface area, and surface functional groups. The pore volume and specific surface area of Fe-AC-0.3 were 0.26 cm3/g and 455.36 m2/g, respectively. The activator played an important role in the formation of the pore structure and morphology of ACP. When the mass ratio was 0–0.3, the porosity increased linearly, but when it was higher than 0.3, the porosity decreased. For example, the pore volume and specific surface area of Fe-AC-0.4 reached 0.24 cm3/g and 430.87 m2/g, respectively. ACP presented good VOC adsorption performance. The Fe-AC-0.3 sample, which contained the most micropore structures, presented the best adsorption capacity for ethyl acetate at 712.58 mg/g. Under the action of the specific reaction products nitrogen dioxide (NO2) and oxygen, the surface of modified ACP samples showed different rich C/O/N surface functional groups, including C-H, C=C, C=O, C-O-C, and C-N.

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