Fe-N-C single-atom catalyst with axial structure prepared by a new design and synthesis method for ORR

2021 ◽  
Author(s):  
Fan Liu ◽  
Ning Yan ◽  
Guangqi Zhu ◽  
Zigeng Liu ◽  
Shenqian Ma ◽  
...  

Fe-N-C single-atom catalyst usually exhibits poor ORR activity due to its unsatisfactory O2 adsorption and activation. Here, a new design ideas and tailored self-assembly synthesis method is reported to improve...

Chem ◽  
2021 ◽  
Author(s):  
Hengyu Li ◽  
Qiang Wan ◽  
CongCong Du ◽  
QiuNan Liu ◽  
Jiamin Qi ◽  
...  

Author(s):  
Yiran Ying ◽  
Ke Fan ◽  
Xin Luo ◽  
Jinli Qiao ◽  
Haitao Huang

Designing high-performance bifunctional oxygen evolution/reduction reaction (OER/ORR) catalysts is a newly emerged topic with wide applications in metal-air batteries and fuel cells. Herein, we report a group of (27) single-atom...


2021 ◽  
Vol 22 (17) ◽  
pp. 9634
Author(s):  
Moran Aviv ◽  
Dana Cohen-Gerassi ◽  
Asuka A. Orr ◽  
Rajkumar Misra ◽  
Zohar A. Arnon ◽  
...  

Supramolecular hydrogels formed by the self-assembly of amino-acid based gelators are receiving increasing attention from the fields of biomedicine and material science. Self-assembled systems exhibit well-ordered functional architectures and unique physicochemical properties. However, the control over the kinetics and mechanical properties of the end-products remains puzzling. A minimal alteration of the chemical environment could cause a significant impact. In this context, we report the effects of modifying the position of a single atom on the properties and kinetics of the self-assembly process. A combination of experimental and computational methods, used to investigate double-fluorinated Fmoc-Phe derivatives, Fmoc-3,4F-Phe and Fmoc-3,5F-Phe, reveals the unique effects of modifying the position of a single fluorine on the self-assembly process, and the physical properties of the product. The presence of significant physical and morphological differences between the two derivatives was verified by molecular-dynamics simulations. Analysis of the spontaneous phase-transition of both building blocks, as well as crystal X-ray diffraction to determine the molecular structure of Fmoc-3,4F-Phe, are in good agreement with known changes in the Phe fluorination pattern and highlight the effect of a single atom position on the self-assembly process. These findings prove that fluorination is an effective strategy to influence supramolecular organization on the nanoscale. Moreover, we believe that a deep understanding of the self-assembly process may provide fundamental insights that will facilitate the development of optimal amino-acid-based low-molecular-weight hydrogelators for a wide range of applications.


CrystEngComm ◽  
2012 ◽  
Vol 14 (9) ◽  
pp. 3125 ◽  
Author(s):  
Hong-Mei Wang ◽  
Yi Han ◽  
Yun-Yin Niu ◽  
Zhen-Hua Zhang ◽  
Hong-Wei Hou ◽  
...  

2011 ◽  
Vol 76 (23) ◽  
pp. 9660-9669 ◽  
Author(s):  
Qing Han ◽  
Quan-Jie Li ◽  
Jiuming He ◽  
Bingjie Hu ◽  
Hongwei Tan ◽  
...  

Author(s):  
Norbert Német ◽  
Ylenia Miele ◽  
Gábor Shuszter ◽  
Eszter L. Tóth ◽  
János Endre Maróti ◽  
...  

AbstractIn the past decade, much effort has been devoted to using chemical clock-type reactions in material design and driving the self-assembly of various building blocks. Urea-urease enzymatic reaction has chemical pH clock behavior in an unbuffered medium, in which the induction time and the final pH can be programmed by the concentrations of the reagents. The urea-urease reaction can offer a new alternative in material synthesis, where the pH and its course in time are crucial factors in the synthesis. However, before using it in any synthesis method, it is important to investigate the possible effects of the reagents on the enzymatic reaction. Here we investigate the effect of the reagents of the zeolite imidazole framework-8 (zinc ions and 2-methylimidazole) on the urea-urease reaction. We have chosen the zeolite imidazole framework-8 because its formation serves as a model reaction for the formation of other metal–organic frameworks. We found that, besides the inhibition effect of the zinc ions which is well-known in the literature, 2-methylimidazole inhibits the enzymatic reaction as well. In addition to the observed inhibition effect, we report the formation of a hybrid urease-zinc-2-methylimidazole hybrid material. To support the inhibition effect, we developed a kinetic model which reproduced qualitatively the experimentally observed kinetic curves.


2018 ◽  
Vol 47 (5) ◽  
pp. 1666-1673 ◽  
Author(s):  
Yan Lv ◽  
Lin Yue ◽  
Qian Li ◽  
Baoyi Shao ◽  
Sen Zhao ◽  
...  

Herein, the design and synthesis of a multifunctional (Fe3O4-NaYF4:Yb,Tm)@TiO2 photocatalyst through a facile sol–gel process combined with electrostatic self-assembly has been reported.


Heterocycles ◽  
2017 ◽  
Vol 95 (1) ◽  
pp. 181
Author(s):  
Hiromitsu Takayama ◽  
Mariko Kitajima ◽  
Akihiro Morita ◽  
Shimpei Endo ◽  
Noriyuki Kogure ◽  
...  

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