Graphene doped ZnS nanoparticles synthesised via hydrothermal route for enhanced electrocatalytic performance

2021 ◽  
Author(s):  
Medha Bhushan ◽  
Ranjana Jha ◽  
Rekha Bhardwaj ◽  
Reetu Sharma
Keyword(s):  
Zns Nanoparticles ◽  
Hydrothermal Route ◽  
Electrocatalytic Performance

ZnS:Ag Luminescent Nanoparticles Synthesized with Different Molar Ratio of S/Zn

2009 ◽  
Vol 79-82 ◽  
pp. 589-592 ◽  
Author(s):  
Hua Qu ◽  
Li Xin Cao ◽  
Ge Su ◽  
Wei Liu ◽  
Yuan Guang Sun ◽  
...  
Keyword(s):  
Blue Emission ◽  
Molar Ratio ◽  
Small Particles ◽  
Sphalerite Structure ◽  
Zns Nanoparticles ◽  
Hydrothermal Preparation ◽  
Hydrothermal Route ◽  
Large Particles ◽  
Luminescent Nanoparticles ◽  
Defect Luminescence

ZnS:Ag (Ag+-doped ZnS) nanoparticles have been synthesized through the hydrothermal route, and the effects of the molar ratio of S/Zn in reagents have been studied. The products are all cubic sphalerite structure, and the crystallinity is generally increased as this ratio rises. The ratio less than 1 leads to small particles less than 10 nm, and the ratio more than 1 leads to large particles between 20~30 nm. Luminescence properties of samples show significant dependence on the ratio. The sample synthesized using stoichiometric reagents during hydrothermal preparation exhibits the strongest blue emission in this series. There is significant defect luminescence in samples synthesized using nonstoichiometric reagents and the Ag-related luminescence is quenched in them.

scholarly journals Luminescence Properties of ZnS Nanoparticles and Porous Nanospheres Synthesized via Co-Precipitation and Hydrothermal Route

2011 ◽  
Vol 9 ◽  
pp. 521-525 ◽  
Author(s):  
Nguyen Tri Tuan ◽  
Nguyen-Duc Trung-Kien ◽  
Pham Thanh Huy ◽  
Nguyen Huyen Tung
Keyword(s):  
Luminescence Properties ◽  
Zns Nanoparticles ◽  
Hydrothermal Route ◽  
Co Precipitation

Effect of Modification Factors of MWCNTs Support on Electrocatalytic Performance of Pt Nanoparticles

2015 ◽  
Vol 30 (9) ◽  
pp. 931 ◽  
Author(s):  
XU Ming-Li ◽  
DUAN Ben ◽  
ZHANG Ying-Jie ◽  
YANG Guo-Tao ◽  
DONG Peng ◽  
...  
Keyword(s):  
Pt Nanoparticles ◽  
Electrocatalytic Performance

Proton Acidity and Proton Mobility in ECR-40, a Silicoaluminophosphate That Violates Löwenstein’s Rule

2019 ◽  
Author(s):  
Michael Fischer
Keyword(s):  
Density Functional ◽  
Water Clusters ◽  
Computational Study ◽  
Acid Catalyst ◽  
Ab Initio Molecular Dynamics ◽  
Brønsted Acidity ◽  
Hydrothermal Route ◽  
Proton Mobility ◽  
Brönsted Acidity ◽  
A Minor

<p>The silicoaluminophosphate zeotype ECR-40, which has the MEI topology, contains linkages of AlO<sub>4</sub> tetrahedra via a common oxygen atom, thereby violating the famous “Löwenstein’s rule”. Due to the proven existence of Al-O-Al linkages in this material, it constitutes an ideal model system to study the acidity and mobility of protons associated with such unusual linkages. In addition, their properties can be directly compared to those of protons associated with more common Si-O-Al linkages, which are also present in ECR-40. In this work, static density functional theory (DFT) calculations including a dispersion correction were employed to study the preferred proton sites as well as the Brønsted acidity of the framework protons, followed by DFT-based ab-initio molecular dynamics (AIMD) to investigate the proton mobility in guest-free and hydrated ECR-40. Initially, two different proton arrangements were compared, one containing both H[O6] protons associated with Al-O-Al linkages and H[O10] protons at Si-O-Al linkages, the other one containing only H[O10] protons. The former model was found to be thermodynamically favoured, as a removal of protons from the Al-O-Al linkages causes a local accumulation of negative charge. Calculations of the deprotonation energy showed a moderately higher Brønsted acidity of the H[O10] protons, at variance with previous empirical explanations, which attributed the exceptional performance of ECR-40 as acid catalyst to the presence of Al‑O‑Al linkages. The AIMD simulations (<i>T</i> = 298 K) delivered no appreciable proton mobility for guest-free ECR-40 and for low levels of hydration (one H<sub>2</sub>O per framework proton). Under saturation conditions, framework deprotonation occurred, leading to the formation of protonated water clusters in the pores. Pronounced differences between the two types of framework protons were observed: While the H[O10] protons were always removed from the Si-O-Al linkages, the Al-O-Al linkages remained mostly protonated, but deprotonation did occur to a minor extent. The observation of a degree of framework deprotonation of Al-O-Al linkages differs from the findings reported in a recent computational study of hydrated aluminosilicate zeolites with such linkages (Heard et al., <i>Chem. Sci.</i> <b>2019</b>, <i>10</i>, 5705), pointing to an influence of the overall framework composition. Further inspection of the AIMD results showed that a coordination of water molecules to framework Al atoms occurred in many cases, especially in the vicinity of the Al-O-Al linkages, sometimes resulting in a pronounced modification of the linkages through additional bridging oxygen atoms. Given the changes in the local structure, it can be expected that such modified linkages are especially prone to break upon dehydration. Thus, in addition to elucidating the deprotonation behaviour of protons associated with different types of linkages, the calculations also provide insights into possible reasons for the instability of Al-O-Al linkages, clarifying why Löwenstein’s rule is mostly obeyed in materials that are formed via a hydrothermal route.</p>

Preparation and Electrocatalytic Performance of Thin-shell Ni/Pt Core-shell Nanoparticles

2012 ◽  
Vol 27 (1) ◽  
pp. 95-101
Author(s):  
Shi-Bin LIU ◽  
Chun-Ying YANG ◽  
Zhong-Lin ZHANG ◽  
Dong-Hong DUAN ◽  
Xiao-Gang HAO ◽  
...  
Keyword(s):  
Thin Shell ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Electrocatalytic Performance ◽  
Core Shell Nanoparticles

Fabrication of Morphology of One-dimensional Nano-γ-AlOOH via Hydrothermal Route

2009 ◽  
Vol 24 (3) ◽  
pp. 463-468 ◽  
Author(s):  
Guang-Wei LU ◽  
Qi YANG ◽  
Yi-Da DENG ◽  
Wen-Bin HU
Keyword(s):  
Hydrothermal Route ◽  
One Dimensional

Growth and local structure analysis of ZnS nanoparticles

2010 ◽  
Vol 405 (17) ◽  
pp. 3700-3703 ◽  
Author(s):  
R. Saravanan ◽  
S. Saravanakumar ◽  
S. Lavanya
Keyword(s):  
Structure Analysis ◽  
Local Structure ◽  
Zns Nanoparticles

ZnS nanoparticles as new additive for polyethersulfone membrane in humic acid filtration

2019 ◽  
Vol 79 ◽  
pp. 71-78 ◽  
Author(s):  
Jing Guo ◽  
Sovann Khan ◽  
So-Hye Cho ◽  
Jeonghwan Kim
Keyword(s):  
Humic Acid ◽  
Zns Nanoparticles ◽  
Polyethersulfone Membrane
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