scholarly journals Electrospun Nanofibers with High Specific Surface Area to Prepare Modified Electrodes for Electrochemiluminescence Detection of Azithromycin

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Hao Cheng ◽  
Xuenuan Li ◽  
Tianhao Li ◽  
Danfeng Qin ◽  
Tingfan Tang ◽  
...  

Polyacrylonitrile (PAN) and (CH3COO)2Zn were used as raw materials, and carbon nanofibers (CNFs) with high specific surface area were successfully prepared by an electrospinning method. A new method of electrochemiluminescence detection of azithromycin was established by modifying the glassy carbon electrode (GCE). Under the optimal conditions, the electrochemical behavior and electrochemiluminescence behavior of the Ru(bpy)32+-AZM system on the modified electrode were investigated. Owing to the large specific area, more active sites, and promotion of electron transfer, the sensor exhibits high electrocatalytic activity, high sensitivity, a good linear relationship ranging from 8.0 × 10 − 8 to 1.0 × 10 − 4  mol/L, and a low detection limit ( 6.52 × 10 − 8  mol/L). In addition, the good recoveries indicate that the sensor was a promising device for the detection of azithromycin in real samples.

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3429
Author(s):  
Lei Zhao ◽  
Ziwei Lan ◽  
Wenhao Mo ◽  
Junyu Su ◽  
Huazhu Liang ◽  
...  

Non-platinum carbon-based catalysts have attracted much more attention in recent years because of their low cost and outstanding performance, and are regarded as one of the most promising alternatives to precious metal catalysts. Activated carbon (AC), which has a large specific surface area (SSA), can be used as a carrier or carbon source at the same time. In this work, stable pine peel bio-based materials were used to prepare large-surface-area activated carbon and then compound with cobalt phthalocyanine (CoPc) to obtain a high-performance cobalt/nitrogen/carbon (Co-N-C) catalyst. High catalytic activity is related to increasing the number of Co particles on the large-specific-area activated carbon, which are related with the immersing effect of CoPc into the AC and the rational decomposed temperature of the CoPc ring. The synergy with N promoting the exposure of CoNx active sites is also important. The Eonset of the catalyst treated with a composite proportion of AC and CoPc of 1 to 2 at 800 °C (AC@CoPc-800-1-2) is 1.006 V, higher than the Pt/C (20 wt%) catalyst. Apart from this, compared with other AC/CoPc series catalysts and Pt/C (20 wt%) catalyst, the stability of AC/CoPc-800-1-2 is 87.8% in 0.1 M KOH after 20,000 s testing. Considering the performance and price of the catalyst in a practical application, these composite catalysts combining biomass carbon materials with phthalocyanine series could be widely used in the area of catalysts and energy storage.


Author(s):  
Chenyu Liu ◽  
Haitong Wei ◽  
Yanhui Gao ◽  
Ning Wang ◽  
Xiaoying Yuan ◽  
...  

Abstract Metal-Organic Frameworks (MOFs) have unique properties and stable structure, which have been widely used as templates/precursors to prepare well-developed pore structure and high specific surface area materials. In this article, an innovative and facile method of crystal reorganization was designed by using MOFs as sacrificial templates to prepare LDH nano-layer sheet structure through a pseudomorphic conversion process under alkaline conditions. The obtained CoMn-LDH and CoFe-LDH catalysts broke the ligand of MOFs and reorganized the structure on the basis of retaining a high specific surface area and a large number of pores, which have higher specific surface area and well-developed pore structure than LDH catalysts prepared by traditional methods, and thus provide more active sites to activate PMS. Due to the unique framework structure of MOFs, the MOF derived CoMn-LDH and CoFe-LDH catalysts could provide more active sites to activate PMS, and achieve a 2, 4-dichlorophenol (2, 4-DCP) degradation of 99.3% and 99.2% within 20 min, respectively. Besides, the two LDH catalysts displayed excellent degradation performance for bisphenol A (BPA), ciprofloxacin (CIP) and 2, 4-dichlorophenoxyacetic acid (2, 4-D). XPS indicated that the valence state transformation of metal elements participated in PMS activation. EPR manifested sulfate radical () and singlet oxygen (1O2) were the main species for degrading pollutants. In addition, after the three-cycle experiment, the CoMn-LDH and CoFe-LDH catalysts also showed long-term stability with a slight activity decrease in the third cycle. The phytotoxicity assessment determined by the germination of mung beans proved that PMS activation by MOFs-derived LDH catalyst can basically eliminate the phytotoxicity of 2, 4-D solution. This research not only developed high-activity LDH catalysts for PMS activation, but also expanded the environmental applications of MOFs derivants.


2005 ◽  
Vol 486-487 ◽  
pp. 37-40
Author(s):  
Jing Sun ◽  
Lian Gao

Rutile TiO2 nanoparticles have been synthesized by direct hydrolysis method using TiCl3, TiCl4 as starting materials, yielding two different morphologies. The hydrolysis of TiCl3 resulted in needlelike rutile titania with the specific surface area of 74.5m2/g, while round particles about 200~400 nm with small acicular at edge, with specific area as high as 175m2/g, were obtained using TiCl4 as starting materials. The precipitates from TiCl4 hydrolysis could be changed into anatase phase without filtering and separation by varying pH of the system. The phenomenon was explained from the viewpoint of structure. The photocatalysed properties of rutile powders were compared with those of anatase of the same specific surface area. Rutile powders with initial crystalline size of 7 nm were found to have higher photocatalysed activity in the phenol degradation reaction than that which anatase has. The high activity of the as prepared lab-made rutile was attributed to the abundance of hydroxy groups in powders, which was proved by TG data, making the degradation reaction have more active sites. The agglomeration form of the rutile powder makes it easy for separation and reuse.


2018 ◽  
Vol 6 (20) ◽  
pp. 9716-9722 ◽  
Author(s):  
Ya-Nan Chen ◽  
Yibo Guo ◽  
Huijuan Cui ◽  
Zhaojun Xie ◽  
Xin Zhang ◽  
...  

MnO@Co–N/C composites were fabricated with excellent bifunctional catalytic activity and outstanding performance for both liquid- and solid-state Zn–air batteries. The excellent electrocatalytic activities are attributed to the unique 1D nanowire structure with abundant Co–Nx active sites and a high specific surface area.


Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4330
Author(s):  
Zheng Luo ◽  
Yinghan Li ◽  
Fengbo Guo ◽  
Kaizhi Zhang ◽  
Kankan Liu ◽  
...  

Climate change has been recognized as a threatening environmental problem around the world. CO2 is considered to be the main component of greenhouse gas. By using solar energy (light energy) as the energy source, photocatalytic conversion is one of the most effective technologies to reveal the clean utilization of CO2. Herein, using sodium tungstate, nickel nitrate, and selenium powder as the main raw materials, the high absorption and utilization of WSe2 for light energy and the high intrinsic conductivity of NiSe2 were combined by a hydrothermal method to prepare NiSe2/WSe2 and hydrazine hydrate as the reductant. Then, high-performance NiSe2/WSe2 photocatalytic material was prepared. The characterization results of XRD, XPS, SEM, specific surface area, and UV-visible spectroscopy show that the main diffraction peak of synthesized NiSe2/WSe2 is sharp, which basically coincides with the standard card. After doping NiSe2, the morphology of WSe2 was changed from a flake shape to smaller and more trivial crystal flakes, which demonstrates richer exposed edges and more active sites; the specific surface area increased from 3.01 m2 g−1 to 8.52 m2 g−1, and the band gap becomes wider, increasing from 1.66 eV to 1.68 eV. The results of a photocatalytic experiment show that when the prepared NiSe2/WSe2 catalyst is used to conduct photocatalytic reduction of CO2, the yield of CH3OH is significantly increased. After reaction for 10 h, the maximum yield could reach 3.80 mmol g−1, which presents great photocatalytic activity.


Nanoscale ◽  
2017 ◽  
Vol 9 (35) ◽  
pp. 13334-13340 ◽  
Author(s):  
Hao Zhang ◽  
Xiaobin Xu ◽  
Haifeng Lin ◽  
Muhammad Aizaz Ud Din ◽  
Haiqing Wang ◽  
...  

Ultrathin nanocrystals generally provide a remarkable catalytic performance due to their high specific surface area and exposure of certain active sites.


Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 345 ◽  
Author(s):  
Lianzan Yang ◽  
Yongyan Li ◽  
Zhifeng Wang ◽  
Weimin Zhao ◽  
Chunling Qin

High-entropy alloys (HEAs) present excellent mechanical properties. However, the exploitation of chemical properties of HEAs is far less than that of mechanical properties, which is mainly limited by the low specific surface area of HEAs synthesized by traditional methods. Thus, it is vital to develop new routes to fabricate HEAs with novel three-dimensional structures and a high specific surface area. Herein, we develop a facile approach to fabricate nanoporous noble metal quasi-HEA microspheres by melt-spinning and dealloying. The as-obtained nanoporous Cu30Au23Pt22Pd25 quasi-HEA microspheres present a hierarchical porous structure with a high specific surface area of 69.5 m2/g and a multiphase approximatively componential solid solution characteristic with a broad single-group face-centered cubic XRD pattern, which is different from the traditional single-phase or two-phase solid solution HEAs. To differentiate, these are named quasi-HEAs. The synthetic strategy proposed in this paper opens the door for the synthesis of porous quasi-HEAs related materials, and is expected to promote further applications of quasi-HEAs in various chemical fields.


2021 ◽  
Vol 45 (12) ◽  
pp. 5712-5719
Author(s):  
Yongxiang Zhang ◽  
Peifeng Yu ◽  
Mingtao Zheng ◽  
Yong Xiao ◽  
Hang Hu ◽  
...  

Porous carbons with a high specific surface area (2314–3470 m2 g−1) are prepared via a novel KCl-assisted activation strategy for high-performance supercapacitor.


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