Catalysis over Supported Metals. V. The Effect of Crystallite Size on the Catalytic Activity of Nickel

1966 ◽  
Vol 70 (7) ◽  
pp. 2257-2263 ◽  
Author(s):  
J. L. Carter ◽  
J. A. Cusumano ◽  
J. H. Sinfelt
Keyword(s):  
Catalytic Activity ◽  
Crystallite Size ◽  
Supported Metals

Influence of Ni2+ Ions on the Structural, Morphological, Photoluminescence, Photo-Catalytic and Anti-Bacterial Studies of Cd0.9Zn0.1S Nanostructures

2021 ◽  
Author(s):  
P. Raju ◽  
Joseph Prince Jesuraj ◽  
S. Muthukumaran
Keyword(s):  
Catalytic Activity ◽  
Crystallite Size ◽  
Energy Gap ◽  
Volume Ratio ◽  
Blue Dye ◽  
Cubic Phase ◽  
Bacterial Killing ◽  
Optical Absorbance ◽  
Photo Catalytic Activity ◽  
Ni Addition

Abstract Controlled synthesis of Cd0.9Zn0.1S and Cd0.89Zn0.1Ni0.01S nanostructures by chemical co-precipitation route was reported. The XRD analysis confirmed the cubic structure of CdS on Zn doping and Zn, Ni dual doping without any secondary/impurity phases and no alteration in cubic phase was noticed by Zn/Ni addition. The shrinkage of crystallite size from 69 Å to 43 Å and the variation in lattice constants and micro-strain were described by the addition of Ni and the defects associated with Ni2+ ions. The enhanced optical absorbance in the visible wavelength and the reduced energy gap by Ni substitution showed that Cd0.89Zn0.1Ni0.01S nanostructures are useful to improve the efficiency of opto-electronic devices. The functional groups of Cd-S / Zn-Cd-S /Zn/Ni-Cd-S and their chemical bonding were verified by Fourier transform infrared studies. The elevated visible PL emissions such as blue and green emissions by Ni addition was explained by worsening of crystallite size and generation of more defects. Zn, Ni dual doped CdS nanostructures are identified as the probable an efficient photo-catalyst for the degradation of methylene blue dye. The liberation of more charge carriers, better visible absorbance, improved surface to volume ratio and the creation of more defects are accountable for the current photo-catalytic activity in Zn/Ni doped CdS which exhibited better photo-catalytic activity after sex cycling process. The noticed higher bacterial killing ability at Ni doped Cd0.9Zn0.1S is due to the collective effect of lower particle/grain size and also higher ROS producing capacity.

Remarkable Activity of Nanoarchitectonics Mesoporous CuO/CeO2–TiO2 Prepared by Nanocasting and Deposition Precipitation Techniques

2020 ◽  
Vol 20 (5) ◽  
pp. 2791-2802
Author(s):  
Duangamol Ongmali ◽  
Sakollapath Pithakratanayothin ◽  
Sureerat Jampa ◽  
Apanee Luengnaruemitrchai ◽  
Thanyalak Chaisuwan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Crystallite Size ◽  
Oxygen Vacancies ◽  
Redox Properties ◽  
Oxygen Defect ◽  
Nitrate Salt ◽  
Hard Template ◽  
Different Levels

In this work, a ceria (CeO2) support was modified with titania (TiO2) by nanocasting using MCM-48 as a hard template and then loading Cu (as the nitrate salt) at different levels (3–9% by weight) by deposition-precipitation followed by calcination. The addition of TiO2 in MSP CeO2 revealed that the MSP CeO2 was significantly improved the oxygen vacancies of the catalyst by increasing the Ce3+ content from 38 to 75% and stabilizing the Ce3+ species by bonding with the oxygen as Ce(4f)-O(2p)-Ti(3d). Moreover, the bonding of MSP CeO2 with TiO2 generated the oxygen defect vacancies (s–Ti3+), allowing Cu2+ to occupy and be reduced to Cu+ during calcination. The smaller CeO2 crystallite size (2.7 nm) of 9Cu/CeO2–TiO2 increased the mass-specific CO-Oxidation, showing the best catalytic activity due to its highest redox properties, as determined by H2-TPR and also showing resistant property to water and carbon dioxide. Indeed, water was adsorbed on the Ce3+ sites, generating OHads which reacted with CO to form –COOH, resulting in CO2.

Catalytic activity of Ni‐Co supported metals in carbon dioxides methanation

2020 ◽  
Vol 98 (9) ◽  
pp. 1924-1934
Author(s):  
Patrizia Frontera ◽  
Angela Malara ◽  
Vincenza Modafferi ◽  
Vincenzo Antonucci ◽  
Pierluigi Antonucci ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Supported Metals

Influence of Fluoride Ion on the Electrochemical Properties of Al/β-PbO2 Electrode

2012 ◽  
Vol 490-495 ◽  
pp. 3160-3166 ◽  
Author(s):  
Zhen Chen ◽  
Jian Wu ◽  
Zhong Cheng Guo ◽  
Qiang Yu
Keyword(s):  
Crystal Structure ◽  
Catalytic Activity ◽  
Electrochemical Properties ◽  
Crystallite Size ◽  
Anode Material ◽  
Fluoride Ion ◽  
Pbo2 Electrodes ◽  
Mechanism Of The Reaction

Al/α-PbO2/β-PbO2 electrodes doped with fluoride ion (NaF) were prepared by anodic co-deposition in order to investigate the influence of NaF dopants on the properties of Al/α-PbO2/β-PbO2 electrodes. In our work, we found fluoride ion will benefit for the crystallization of β-PbO2 and change the crystallite size, crystal structure, enhance the catalytic activity, and even change the mechanism of the reaction in the oxidation of the material. The presence of NaF in the β-PbO2 electrolyte could enhance the electrochemical properties of the coating and therefore make itself as a superior anode material.

Line Broadening Studies on Highly Defective TiO2 Produced by High Pressure Shock Loading

1983 ◽  
Vol 27 ◽  
pp. 379-388
Author(s):  
B. Morosin ◽  
E. J. Graeber ◽  
R. A. Graham
Keyword(s):  
High Pressure ◽  
Catalytic Activity ◽  
Crystallite Size ◽  
Shock Loading ◽  
Lattice Strain ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Pressure Shock ◽  
X Ray ◽  
Large Numbers

Enhanced solid state reactivity of materials both during and after shock compression has been attributed to the introduction of large numbers of defects into the crystalline lattices and to reduction in the particle and crystallite size of powders [1]. In particular, orders of magnitude increases in the catalytic activity has been observed In shock-modified TiO2 [2]. Line broadening of x-ray diffraction profiles provides a means to determine the coherent crystallite size and the residual lattice strain resulting from defect concentrations. The present study on shock-loaded rutile is a detailed Investigation of the influence of shock loading on residual lattice strain and coherent crystallite size. Annealing of shock-modified rutile powders is also studied.

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