A Novel TEPA-Load or PEI-Load Beta/KIT-6 Composite and their Application to CO2 Adsorption

NANO ◽  
2021 ◽  
pp. 2150033
Author(s):  
Yu Li ◽  
Jianwen Wei ◽  
Linlin Geng ◽  
Dejun Mei ◽  
Lei Liao

An amine-modified Beta/KIT-6 (BK) micro/mesoporous composite for CO2 capture was synthesized using nonionic tri-block copolymer pluronic (P123) as a template, tetraethyl orthosilicate (TEOS) as a silicon source and Beta zeolite as part of silicon aluminum source by a two-step hydrothermal crystallization method. BK was modified by Tetraethylenepentamine (TEPA) or polyethyleneimine (PEI) to obtain solid amine adsorbent. The structure, uniformity and physical properties of the sample were characterized by FTIR, nitrogen adsorption/desorption and elemental analysis methods and CO2 adsorption/desorption behavior of adsorbents and regeneration performance were investigated by thermal gravimetric analysis (TGA). Experimental results showed that with the increase of amine loading the CO2 adsorption capacity of samples increased first and then decreased at [Formula: see text]C, TEPA-loaded BK and PEI-loaded BK both presented the largest saturated CO2 adsorption capacity when the amine loading reached 60%, and the maximum values were 4.21[Formula: see text]mmol[Formula: see text]g[Formula: see text] and 2.72[Formula: see text]mmol[Formula: see text]g[Formula: see text], respectively. BK-TEPA-60 and BK-PEI-60 reached the maximum adsorption capacity at [Formula: see text]C and [Formula: see text]C. The adsorption kinetics analysis showed that the adsorption process of amine-modified BK was dominated by both physical and chemical adsorption. After five cycles of adsorption/desorption, BK-PEI-60 kept better stability with the equilibrium adsorption capacity of exhibited just 2.9% attrition, whereas a 9.2% decrease was obtained for BK-TEPA-60. Compared with other amine-modified solid materials, the materials we designed show good CO2 adsorption performance, indicating that they are promising efficient adsorbents for CO2 capture.

2021 ◽  
Author(s):  
You Wu ◽  
Zuannian Liu ◽  
Bakhtari Mohammad Fahim ◽  
Junnan Luo

Abstract In this study, MIL-101(Fe), MIL-101(Fe,Cu), and Graphene Oxide (GO) /MIL-101(Fe,Cu) were synthesized to compose a novel sorbent. The adsorption properties of these three MOFs-based composites were compared toward the removal of phosphate. Furthermore, the influencing factors including reaction time, pH, temperature and initial concentration on the adsorption capacity of phosphate on these materials as well as the reusability of the material were discussed. The structure of fabricated materials and the removal mechanism of phosphate on the composite material were analyzed by Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption analysis and zeta potential. The results show that the maximum adsorption capacity of phosphate by the composite GO/MIL-101(Fe,Cu)-2% was 204.60 mg·g− 1, which is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe). likewise the specific surface area of GO/MIL-101(Fe,Cu)-2% is 778.11 m2/g is higher than that of MIL-101(Fe,Cu) and MIL-101(Fe),which are 747.75 and 510.66m2/g respectively. The adsorption mechanism of phosphate is electrostatic attraction, form coordination bonds and hydrogen bonds. The fabricated material is a promising adsorbent for the removal of phosphate with good reusability.


NANO ◽  
2018 ◽  
Vol 13 (04) ◽  
pp. 1850042 ◽  
Author(s):  
Jianwen Wei ◽  
Dejun Mei ◽  
Zhifeng Lin ◽  
Linlin Geng ◽  
Siqi Chen ◽  
...  

Mesoporous silica pore-expanded KIT-6 was synthesized using tetraethoxysilane (TEOS) as the silica source, tri-block copolymer (P123) as a structure-directing agent and 1,3,5-trimethylbenzene (TMB) as swelling agents by a hydrothermal method. Then, pore-expanded KIT-6 (PE-KIT-6) was modified with different amounts of amines including triethylenetetramine (TETA) and tetraethylenepentamine (TEPA) by a post-synthetic impregnation method. The samples were characterized by small-angle X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 adsorption/desorption, elemental analysis and thermal gravimetric analysis (TGA). Experimental results revealed that the modifiers were introduced into the samples and the CO2 adsorption capacity increased first and then decreased with the increase of TETA/TEPA loadings. Under the same loadings of TETA/TEPA, the samples modified by TEPA exhibited better CO2 adsorption capacities than the samples modified by TETA because TEPA has one more amine group than TETA in the molecule. The results also indicated that the samples had good adsorption capacities at the loadings ranging from 30% to 35%. Among them, the sample modified by TEPA with the loading of 35% had the maximum adsorption capacity of 2.9[Formula: see text]mmol/g. After five cycles of adsorption/desorption, the adsorption capacity only dropped 4.59%, indicating that the adsorbent of PE-KIT-6 modified by TEPA has good cyclic stability.


Author(s):  
Qin-Hui Zhang ◽  
Shao-Peng Li ◽  
Shu-Ying Sun ◽  
Xian-Sheng Yin ◽  
Jian-Guo Yu

This paper highlights our recent work on preparation and characterization of nanostructure transition metal (Me) oxide (Me = Mn, Ti and Zr) ion-sieves. The controlled hydrothermal and Sol-Gel method have been developed in the synthesis of ion-sieves by the acid treatment of Li-Me-O tri-oxide precursors. The structure characteristic and ion-exchange property are studied by XRD, TEM, nitrogen adsorption-desorption analysis, lithium ion adsorptive isotherm and kinetics measurement. The result shows that these transition metal oxide ion-sieves, promising in the lithium extraction from brine or seawater, have good selectivity and remarkable adsorption capacity for lithium ions. The maximum adsorption capacity of manganese dioxide and titania by now is 3.47 and 4.02 mmol/g, respectively. The adsorption capacity of zirconia ion-sieve is only 0.675 mmol/g. To the best of our knowledge there is no other report on zirconia with the lithium adsorption property up-to-date.


2019 ◽  
Vol 128 (1B) ◽  
pp. 5
Author(s):  
Nguyễn ĐỨC Vũ Quyên ◽  
Trần Ngọc Tuyền ◽  
Đinh Quang Khiếu ◽  
Đặng Xuân Tín ◽  
Bùi Thị Hoàng Diễm ◽  
...  

Carbon nanotubes (CNTs) synthesized by chemical vapour deposition without using hydrogen were oxidized with 0.1 M potassium permanganate at 40<sup>o</sup>C for 2 hours and exhibited high Cu<sup>II</sup> adsorption capacity from aqueous solution. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM) and nitrogen adsorption/desorption isotherms were used to characterize the oxidized CNTs. After oxidizing, the obtained CNTs were used to remove Cu<sup>II</sup> from aqueous solution. With Cu<sup>II</sup> initial concentration of 20 mg.L<sup>-1</sup>, at pH of 4 and adsorbent dosage of 0.2 g.L<sup>-1</sup>, the oxidized CNTs exhibited high Cu<sup>II</sup> adsorption ability with maximum adsorption capacity of 174.4 mg.g<sup>-1</sup>.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2295
Author(s):  
Marwa El-Azazy ◽  
Ahmed S. El-Shafie ◽  
Hagar Morsy

Biochars (BC) of spent coffee grounds, both pristine (SCBC) and impregnated with titanium oxide (TiO2@SCBC) were exploited as environmentally friendly and economical sorbents for the fluroquinolone antibiotic balofloxacin (BALX). Surface morphology, functional moieties, and thermal stabilities of both adsorbents were scrutinized using SEM, EDS, TEM, BET, FTIR, Raman, and TG/dT analyses. BET analysis indicated that the impregnation with TiO2 has increased the surface area (50.54 m2/g) and decreased the pore size and volume. Batch adsorption experiments were completed in lights of the experimental set-up of Plackett-Burman design (PBD). Two responses were maximized; the % removal (%R) and the adsorption capacity (qe, mg/g) as a function of four variables: pH, adsorbent dosage (AD), BALX concentration ([BALX]), and contact time (CT). %R of 68.34% and 91.78% were accomplished using the pristine and TiO2@SCBC, respectively. Equilibrium isotherms indicated that Freundlich model was of a perfect fit for adsorption of BALX onto both adsorbents. Maximum adsorption capacity (qmax) of 142.55 mg/g for SCBC and 196.73 mg/g for the TiO2@SCBC. Kinetics of the adsorption process were best demonstrated using the pseudo-second order (PSO) model. The adsorption-desorption studies showed that both adsorbents could be restored with the adsorption efficiency being conserved up to 66.32% after the fifth cycles.


2017 ◽  
Vol 36 (1-2) ◽  
pp. 198-214 ◽  
Author(s):  
Kaiyue Wu ◽  
Jingang Yu ◽  
Xinyu Jiang

Multi-walled carbon nanotubes (MWCNTs) encapsulated by polyaniline (PANI) were synthesized by in situ polymerization. Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and thermal gravimetric analysis (TGA) were used to characterize the synthesized composites (O-MWCNTs/PANI), and the surface area was calculated by the Brunauer–Emmett–Teller (BET) method. The removal capacity of alizarin yellow R (AYR) with O-MWCNTs/PANI was further investigated. Experiments were conducted to optimize the adsorption conditions, including contact time, pH, initial concentration of AYR and temperature. The results showed that the maximum adsorption capacity for AYR was 884.80 mg/g. The adsorption kinetics and the adsorption isotherm could be better described by the pseudo-second-order model and the Langmuir isotherm, respectively. Energy changes revealed that the adsorption process was exothermic and spontaneous in nature. Additionally, the O-MWCNTs/PANI showed higher adsorption capacity than pristine MWCNTs or PANI. Therefore, O-MWCNTs/PANI would be applied as an efficient adsorbent for the removal of dye from water.


2018 ◽  
Vol 775 ◽  
pp. 376-382 ◽  
Author(s):  
Alzhan Baimenov ◽  
Dmitriy Berillo ◽  
Leila Abylgazina ◽  
Stavros G. Poulopoulos ◽  
Vassilis J. Inglezakis

In this work, amphoteric cryogels based on N,N-dimethyl acrylamide, methacrylic acid and allylamine, crosslinked by N,N-methylenebisacrylamide were synthesized by free-radical polymerization in cryo-conditions. The synthesized cryogels were used for the removal of cadmium ions from aqueous solutions under different pH values. The chemical structure was studied by FTIR, porosity by nitrogen adsorption and morphology by scanning electron microscopy and texture analyzer. The amphoteric properties of cryogels were studied by zeta potential measurements. Adsorption tests revealed that cryogels exhibit 3 times higher adsorption capacity at pH 6.0 than at pH 4.0. The maximum adsorption capacity of the amphoteric cryogels for Cd2+ was 113 mg/g, at pH 6.0 and initial Cd2+ concentration 100 ppm. The results suggest that the predominant removal mechanism is ion exchange between sodium, which initially presents in the structure of the cryogel, and cadmium from the aqueous phase. Recovery studies suggested that the cryogels used can be regenerated and efficiently reused.


2017 ◽  
Vol 77 (3) ◽  
pp. 628-637 ◽  
Author(s):  
Shuangzhen Guo ◽  
Jian Zhang ◽  
Xianlong Li ◽  
Fan Zhang ◽  
Xixi Zhu

Abstract A novel core-shell bio-adsorbent was fabricated by using biological materials for removing methyl orange (MO) from aqueous solution. The structure characteristics results of scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), thermo-gravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) shows that Fe3O4-CS-L has been successfully prepared. The effects of contact time, pH, temperature and initial concentration were explored. The results suggested pH was a negligible factor in adsorption progress. Kinetic studies showed that the experiment data followed pseudo-second-order model. Boyd mode suggested that external mass transfer showed a rather weak rate control for MO adsorption onto Fe3O4-CS-L. Equilibrium studies showed that isotherm data were the best described by Langmuir model. The maximum adsorption capacity of MO estimated to be 338.98 mg/g at 298 K. Moreover, the adsorption capacity of Fe3O4-CS-L can keep about 74% in the fifth adsorption–regeneration cycle. Thus, the Fe3O4-CS-L could be a kind of promising material for removing MO from wastewater.


2017 ◽  
Vol 42 (3) ◽  
pp. 269-281
Author(s):  
Lvling Zhong ◽  
Liang Zhang ◽  
Hongliang Shi

A series of nitrogen-doped mesoporous carbons (NDMCs) was prepared using p-phenylenediamine and glyoxal as a carbon source and mesoporous silica as a hard template. N2 adsorption–desorption isotherms indicated that mesopores with a wider distribution exist in NDMCs. Elemental analysis showed that the N content on the surface of NDMC-800 was 9.9at.%, with a result close to 8.4at.% from X-ray photoelectron spectroscopy. The adsorption capacity of NDMCs for crystal violet (CV) in aqueous solution was investigated. Static equilibrium data were well described by the Langmuir isotherm model, with a maximum adsorption capacity of 243.9 mg g−1. Adsorption kinetics data suggested that the adsorption control process follows the pseudo first-order kinetics model. The results showed that this carbon material has the potential for application in adsorption of CV.


2021 ◽  
Vol 11 (5) ◽  
pp. 13130-13140

Our study aims to evaluate the efficiency of dissolved iron (III) retention in synthetic solutions by adsorption on treated natural phosphate collected in the Khouribga region. This research focused on the valorization of phosphate, a naturally occurring resource that is abundant in Morocco. The resulting products were analyzed by various methods, including FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). In this work, we studied the effect of several parameters such as adsorbent amount, contact time, solution pH, and initial concentration of iron (III) on the adsorption process. The results of the adsorption of iron (III) indicate that the efficiency was achieved after 5 minutes, and the maximum adsorption capacity calculated from the Langmuir model was 26.18 mg g-1. The regeneration and reuse of synthesized adsorbent are effective for five cycles of adsorption-desorption cycles without reducing adsorption capacity.


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