A new paradigm of ultrathin 2D nanomaterial adsorbents in aqueous media: graphene and GO, MoS2, MXenes, and 2D MOFs

2019 ◽  
Vol 7 (28) ◽  
pp. 16598-16621 ◽  
Author(s):  
Pin Zhao ◽  
Meipeng Jian ◽  
Qi Zhang ◽  
Rongming Xu ◽  
Ruiping Liu ◽  
...  

Due to the high surface area, atomic-level thickness, and abundant exposed active sites, 2D nanomaterials are regarded potential high-performance adsorbents. We review four representative nanomaterials, graphene, MoS2, MXenes, and MOFs, for this application.

2016 ◽  
Vol 6 (5) ◽  
pp. 1435-1441 ◽  
Author(s):  
Seyed Mohsen Sadeghzadeh

In this study, a novel fibrous nanosilica (KCC-1) based nanocatalyst (Au, Pd, and Cu) with a high surface area and easy accessibility of active sites was successfully developed by a facile approach.


Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 249 ◽  
Author(s):  
Soukaina Akel ◽  
Redouan Boughaled ◽  
Ralf Dillert ◽  
Mohamed El Azzouzi ◽  
Detlef W. Bahnemann

Pharmaceuticals, especially antibiotics, constitute an important group of aquatic contaminants given their environmental impact. Specifically, tetracycline antibiotics (TCs) are produced in great amounts for the treatment of bacterial infections in both human and veterinary medicine. Several studies have shown that, among all antibiotics, oxytetracycline hydrochloride (OTC HCl) is one of the most frequently detected TCs in soil and surface water. The results of the photocatalytic degradation of OTC HCL in aqueous suspensions (30 mg·L−1) of 0.5 wt.% cobalt-doped TiO2 catalysts are reported in this study. The heterogeneous Co-TiO2 photocatalysts were synthesized by two different solvothermal methods. Evonik Degussa Aevoxide P25 and self-prepared TiO2 modified by the same methods were used for comparison. The synthesized photocatalysts were characterized by X-ray powder diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), UV/vis diffuse reflectance spectroscopy (DRS), and N2 adsorption (BET) for specific surface area determination. The XRD and Raman results suggest that Ti4+ was substituted by Co2+ in the TiO2 crystal structure. Uv/visible spectroscopy of Co-TiO2-R showed a substantial redshift in comparison with bare TiO2-R. The photocatalytic performance of the prepared photocatalysts in OTC HCL degradation was investigated employing Uv/vis spectroscopy and high-performance liquid chromatography (HPLC). The observed initial reaction rate over Co-TiO2-R was higher compared with that of Co-TiO2-HT, self-prepared TiO2, and the commercial P25. The enhanced photocatalytic activity was attributed to the high surface area (153 m2·g−1) along with the impurity levels within the band gap (2.93 eV), promoting the charge separation and improving the charge transfer ability. From these experimental results, it can be concluded that Co-doping under reflux demonstrates better photocatalytic performances than with the hydrothermal treatment.


Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1385
Author(s):  
Botagoz Zhuman ◽  
Shaheen Fatima Anis ◽  
Saepurahman ◽  
Gnanapragasam Singravel ◽  
Raed Hashaikeh

Zeolite-based catalysts are usually utilized in the form of a composite with binders, such as alumina, silica, clay, and others. However, these binders are usually known to block the accessibility of the active sites in zeolites, leading to a decreased effective surface area and agglomeration of zeolite particles. The aim of this work is to utilize carbon nanostructures (CNS) as a binding material for nano-zeolite-Y particles. The unique properties of CNS, such as its high surface area, thermal stability, and flexibility of its fibrous structure, makes it a promising material to hold and bind the nano-zeolite particles, yet with a contemporaneous accessibility of the reactants to the porous zeolite structure. In the current study, a nano-zeolite-Y/CNS composite catalyst was fabricated through a ball milling approach. The catalyst possesses a high surface area of 834 m2/g, which is significantly higher than the conventional commercial cracking catalysts. Using CNS as a binding material provided homogeneous distribution of the zeolite nanoparticles with high accessibility to the active sites and good mechanical stability. In addition, CNS was found to be an effective binding material for nano-zeolite particles, solving their major drawback of agglomeration. The nano-zeolite-Y/CNS composite showed 80% conversion for hexadecane catalytic cracking into valuable olefins and hydrogen gas, which was 14% higher compared to that of pure nano-zeolite-Y particles.


RSC Advances ◽  
2020 ◽  
Vol 10 (50) ◽  
pp. 30214-30222
Author(s):  
Bolong Jiang ◽  
Jiaojing Zhang ◽  
Yanguang Chen ◽  
Hua Song ◽  
Tianzhen Hao ◽  
...  

Co3O4/MCM-41 adsorbent with high surface area and more active sites was successfully prepared by ultrasonic assisted impregnation (UAI) technology and it has been found that the sulfur capacity was improved by 33.2% because of ultrasonication.


2021 ◽  
Vol 7 (2) ◽  
pp. 15-19
Author(s):  
S. M. Yusof ◽  
L. P. Teh

In recent years, there has been growing interest in adsorbents with high surface area, high porosity, high stability and high selectivity for CO2 adsorption. By the incorporation of the additive on the supports such as zeolite, silica, and carbon, the physicochemical properties of the adsorbent and CO2 adsorption performance can be enhanced. In this review, we focus on the overview of bifunctional materials (BFMs) for CO2 adsorption. The findings of this study suggests that the high surface area and high porosity of the support provide a good medium for high dispersion and accessibility of additives (amine or metal oxide), enhancing the CO2 adsorption efficiency. The excessive additive however may lead to a decrease of CO2 adsorption performance due to pore blockage and the decrease of active sites for CO2 interactions. The synergistic relationship of the supporting material and additive is significant towards the enhancement of CO2 adsorption.


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