scholarly journals Special Issue: Layered Double Hydroxides (LDH) and LDH-Based Hybrid Composites

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2582
Author(s):  
Jakub Matusik

LDHs are a class of two-dimensional layered anionic structures with unique properties [...]

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 57 ◽  
Author(s):  
Stamate ◽  
Pavel ◽  
Zavoianu ◽  
Marcu

Layered double hydroxides (LDH) are an extended class of two-dimensional anionic materials that are known for their unique lamellar structure, versatile composition, and tunable properties. The layered architecture allows the intercalation between the positively charged sheets of a vast variety of anionic species, including oxometalates and polyoxometalates (POM). The hybrid composites that were developed using POM and LDH show great advantages when compared to both parent materials causing the appearance of new functionalities, which may lead to remarkable contributions in many areas of application, especially in catalysis. The current review paper emphases all of the crucial works already existing in literature that are related to the large group of POM-LDH solids and their use as catalysts for fine organic synthesis. The new trends in the development of the POM-LDH catalysts are highlighted based on the overview of 121 scientific articles that were published between 1984 and 2019. The main topics are focused primarily on the synthesis, characterization, and the catalytic applications of different LDH systems hosting polyoxometalates with low, medium, and high nuclearity. The intense exploration of the POM-LDH field has led to the obtaining of countless effective catalysts used in various types of reactions, from condensation, esterification, halodecarboxylation, to oxidation and epoxidation.


2018 ◽  
Vol 8 (11) ◽  
pp. 2099 ◽  
Author(s):  
Osama Saber ◽  
Abdullah Aljaafari ◽  
Sarah Asiri ◽  
Khalid Batoo

The present study has a dual aim of supporting magnetic nanoparticles over the nanolayers of LDHs and designing two-dimensional magnetic nano-nets of cobalt ferrite. In this trend, nanoparticles of CoFe2O4 were prepared and supported by Co-Fe LDH through urea hydrolysis. The nanolayered structures of Co-Fe LDH were confirmed by X-ray diffraction, energy-dispersive X-ray spectrometry, FT-IR spectra, thermal analyses, and transmission electron microscopy. In addition, they indicated that 13.2% CoFe2O4 were supported over Co-Fe LDH. Transformation of the nanolayered structures of Co-Fe LDH to nano-nets was achieved by the catalytic effect of the supported CoFe2O4 nanoparticles through solvent thermal technique. X-ray diffraction patterns and transmission electron microscopy images confirmed the transformation of the supported Co-Fe LDH to nano-nets of cobalt ferrite. In order to indicate the effect of the LDH for designing the nano-nets, nanoparticles of cobalt ferrite were prepared by the same technique without LDH. The magnetic behavior of the nano-nets and the supported Co-Fe LDH were measured and compared with the nanoparticles through vibrating sample magnetometer technique. The magnetic parameters indicated that the prepared nano-nets have ferromagnetic behavior and high coercivity. However, the prepared nanoparticles revealed a superparamagnetic state and low coercivity. The experimental results concluded that the incorporation of nanoparticles with nanowires into nano-net structures has been found to be an efficient way to improve their magnetic properties and prevent their agglomerations. Finally, layered double hydroxides are an important source for constructing magnetic nanolayered structures and nano-nets.


Author(s):  
Jie Yu ◽  
Feng Yu ◽  
Muk-Fung Yuen ◽  
Chundong Wang

The Oxygen Evolution Reaction (OER) plays an essential role in hydrogen production for water splitting, metal-air secondary batteries, and artificial photosynthesis. Among the various OER catalysts, layered double hydroxides (LDHs)...


2019 ◽  
Vol 3 (1) ◽  
pp. 237-244 ◽  
Author(s):  
Xueyan Xue ◽  
Feng Yu ◽  
Banghua Peng ◽  
Gang Wang ◽  
Yin Lv ◽  
...  

Layered double hydroxide materials with two-dimensional structures and rich diversity have proved to be very promising candidates for non-precious metal electrocatalysis of the oxygen evolution reaction.


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