Highly Loading Metal Atoms on Graphdiyne for Efficient Nitrogen Fixation to Ammonia

Author(s):  
Yuliang Li ◽  
Yan Fang ◽  
Yurui Xue ◽  
Lan Hui ◽  
Xi Chen

Atomic catalysts have shown great potentials in the field of catalysis because of their maximum atomic utilization, high reaction selectivity and activity. Graphdiyne-based atomic catalysts have emerged as a new...

2021 ◽  
Vol 23 (14) ◽  
pp. 8784-8791
Author(s):  
Qingling Meng ◽  
Ling Zhang ◽  
Jinge Wu ◽  
Shuwei Zhai ◽  
Xiamin Hao ◽  
...  

Theoretical screening of transition metal atoms anchored on monolayer C9N4 as highly stable, catalytically active and selective single-atom catalysts for nitrogen fixation.


2020 ◽  
Vol 22 (17) ◽  
pp. 9216-9224 ◽  
Author(s):  
Zhen Feng ◽  
Yanan Tang ◽  
Weiguang Chen ◽  
Yi Li ◽  
Renyi Li ◽  
...  

2D graphdiyne is a superior candidate for dispersing single transition metal atoms, which can be used as SACs for nitrogen fixation.


2007 ◽  
Vol 55 (5) ◽  
pp. 117-125 ◽  
Author(s):  
G. Park ◽  
M. Yu ◽  
J. Go ◽  
E. Kim ◽  
H. Kim

Among the chemicals causing taste and odour (T&O) in drinking water, the most commonly identified and problematic ones are geosmin and 2-MIB (2-methylisoborneol). Since the reported odour thresholds of geosmin and 2-MIB are as low as 4 and 8.5 ng/L, respectively, they are not readily removed by conventional water treatment processes. In this study, ozone (O3) and ferrate (Fe(VI)) were applied to oxidise geosmin and 2-MIB. Their performances were compared in terms of removal efficiency of geosmin and 2-MIB. In the case of O3, removal efficiency of geosmin and 2-MIB ozonation at different initial O3 doses, H2O2/O3 ratios and water temperatures were evaluated. The oxidation rates of geosmin and 2-MIB by Fe(VI) were measured within pH 6–8. The effect of H2O2 addition was also evaluated. In summary, O3, especially with H2O2, could almost completely oxidise geosmin and 2-MIB, while Fe(VI) could not oxidise them more than 25% at any pH that was considered in this study. This was attributed to the structure of the organics and high reaction selectivity of Fe(VI). Further study should be conducted to find the reason of inhibition of oxidation by Fe(VI).


2018 ◽  
Vol 6 (44) ◽  
pp. 21941-21948 ◽  
Author(s):  
Xingzhu Chen ◽  
Xiujian Zhao ◽  
Zhouzhou Kong ◽  
Wee-Jun Ong ◽  
Neng Li

Single transition metal atoms supported by defective g-C3N4 are examined by DFT for electrochemical N2 fixation. The single Ti atom is the most promising candidate for its high activity and stability owing to the coordination number of the active center.


Author(s):  
S. Ritchie ◽  
J. C. Bennett ◽  
A. Prodan ◽  
F.W. Boswell ◽  
J.M. Corbett

A continuous sequence of compounds having composition NbxTa1-xTe4; 0 ≤ x ≤ 1 have been studied by electron diffraction and microscopy. Previous studies have shown that the end members of the series, TaTε4 and NbTε4 possess a quasi-one-dimensional character and exhibit charge density wave (CDW) distortions. In these compounds, the subcell structure is tetragonal with axes (a × a × c) and consists of the metal atoms (Nb or Ta) centered within an extended antiprismatic cage of Te atoms. At room temperature, TaTε4 has a commensurate modulation structure with a 2a × 2a × 3c unit cell. In NbTε4, an incommensurate modulation with × ∼ 16c axes is observed. Preliminary studies of the mixed compounds NbxTα1-xTε4 showed a discontinuous jump of the modulation wave vector commensurate to incommensurate when the Nb dopant concentration x, exceeded x ≃ 0.3, In this paper, the nature of the compositional dependence of is studied in greater detail and evidence is presented for a stepwise variation of . This constitutes the first direct evidence for a Devil's staircase in CDW materials.


Author(s):  
Klaus-Ruediger Peters

Topographic ultra high resolution can now routinely be established on bulk samples in cold field emission scanning electron microscopy with a second generation of microscopes (FSEM) designed to provide 0.5 nm probe diameters. If such small probes are used for high magnification imaging, topographic contrast is so high that remarkably fine details can be imaged on 2DMSO/osmium-impregnated specimens at ribosome surfaces even without a metal coating. On TCH/osmium-impregnated specimens topographic resolution can be increased further if the SE-I imaging mode is applied. This requires that beam diameter and metal coating thickness be made smaller than the SE range of ~1 nm and background signal contributions be reduced. Subnanometer small probes can be obtained (only) at high accelerating voltages. Subnanometer thin continuous metal films can be produced under the following conditions: self-shadowing effect between metal atoms must be reduced through appropriate deposition techniques and surface mobility of metal atoms must be diminished through high energy sputtering and/or specimen cooling.


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