scholarly journals Chloride Removal of Calcium Aluminate-Layered Double Hydroxide Phases: A Review

2021 ◽  
Vol 18 (6) ◽  
pp. 2797
Author(s):  
Gwangmok Kim ◽  
Sangwon Park
Keyword(s):  
Layered Double Hydroxides ◽  
Calcium Aluminate ◽  
Removal Rate ◽  
Structural Characteristics ◽  
Underlying Mechanism ◽  
Industrial Wastes ◽  
Synthesis Methods ◽  
Critical Element ◽  
Chloride Removal ◽  
Double Hydroxides

Chlorine is a critical element with respect to the use of fossil fuel, recycling of industrial wastes, and water purification. Chlorine could form toxic chemical compounds, corrode pipe systems and boilers, and contaminate surface and ground waters. Calcium aluminate-layered double hydroxides are one of the most promising materials to remove chlorides due to the chemisorption mechanism, since the phases have positively charged interlayers. Many studies on the synthesis and the characterization of calcium aluminate-layered double hydroxides have been extensively conducted, whereas few studies have been conducted on the chloride removal characteristics of the phases. The state-of-the-art studies on the synthesis methods and the structural characteristics of CaAl-LDH phases, the underlying mechanism on the removal of chlorides, and the potential removal rate and the capacity in the present study were thoroughly reviewed.

scholarly journals LAYERED DOUBLE HYDROXIDES: NANOMATERIALS FOR APPLICATIONS IN AGRICULTURE

2015 ◽  
Vol 39 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Luíz Paulo Figueredo Benício ◽  
Rejane Alvarenga Silva ◽  
Júnia Aparecida Lopes ◽  
Denise Eulálio ◽  
Rodrigo Morais Menezes dos Santos ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Layered Double Hydroxides ◽  
Slow Release ◽  
Structural Characteristics ◽  
Synthesis Methods ◽  
Double Hydroxides ◽  
Near Future

The current research aims to introduce Layered Double Hydroxides (LDH) as nanomaterials to be used in agriculture, with particular reference to its use as storage and slow release matrix of nutrients and agrochemicals for plant growing. Structural characteristics, main properties, synthesis methods and characterization of LDH were covered in this study. Moreover, some literature data have been reported to demonstrate their potential for storage and slow release of nitrate, phosphate, agrochemicals, besides as being used as adsorbent for the wastewater treatment. This research aims to expand, in near future, the investigation field on these materials, with application in agriculture, increasing the interface between chemistry and agronomy.

scholarly journals High efficient photocatalytic activity of Zn-Al-Ti layered double hydroxides nanocomposite

2018 ◽  
Vol 149 ◽  
pp. 01087 ◽  
Author(s):  
F. Amor ◽  
A. Diouri ◽  
I. Ellouzi ◽  
F. Ouanji ◽  
M. Kacimi
Keyword(s):  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Uv Irradiation ◽  
Layered Double Hydroxides ◽  
Removal Rate ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
High Efficient ◽  
Double Hydroxides

This work establishes a simple method for synthesising layered double hydroxides (LDHs) powders with coprecipitation. The characteristics of the samples were investigated y X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectrophotometer UV–Vis (DRS). Non-uniform distribution was shown for LDHs samples by SEM. Photocatalytic efficiencies were tested using methylene blue (MB) dye as a model contaminant under UV irradiation. In particular, Zn–Al-Ti LDH exhibited an excellent performance towards MB degradation compared with commercial TiO2 nanoparticles. Methylene blue removal percentage was reached at almost 100%, whereas commercial TiO2 reached a removal rate of only 66% under the same conditions within 20 min. The aim of the current work is to prepare Zn-Al-Ti layered double hydroxides nanocomposite and to evaluate their photocatalytic activity in the removal of methylene blue under UV irradiation.

scholarly journals Study of the textural properties of some layered double hydroxides

2013 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Cornelia-Magda Puscasu ◽  
Carmen Gherasim ◽  
Dragos Mardare ◽  
Gabriela Carja
Keyword(s):  
Layered Double Hydroxides ◽  
Structural Characteristics ◽  
Chemical Species ◽  
Textural Properties ◽  
Layered Compounds ◽  
Layered Compound ◽  
X Ray Diffraction ◽  
Anionic Clays ◽  
Interlayer Region ◽  
Double Hydroxides

Abstract Layered double hydroxides (LDHs) are one of the nano ordered layered compounds. The importance of layered compound is based on their ability to retain chemical species with electrical charges compatible to those of the layers. They may be used in areas such as catalysis, industry, medicine, environmental protection, construction etc. Layered double hydroxides are anionic clays comprising positively charged layers with anions and water molecules intercalated in the interlayer region. The aim of this work was to obtain Cu and/or Ni substituted layered double hydroxides with different micromorphology characteristics. The obtained results pointed out that the relationship between LDHs composition and their textural properties can be controlled. The layered double hydroxides samples were fabricated by using direct coprecipitation method. Field Emission Scanning Electron Microscope (FE-SEM) and X-Ray Diffraction (XRD) analyses were used to study the textural characteristics and the structural characteristics of the samples.

scholarly journals Recent Advances in Self-Supported Layered Double Hydroxides for Oxygen Evolution Reaction

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Libo Wu ◽  
Luo Yu ◽  
Xin Xiao ◽  
Fanghao Zhang ◽  
Shaowei Song ◽  
...  
Keyword(s):  
Water Splitting ◽  
Oxygen Evolution ◽  
Layered Double Hydroxides ◽  
Oxygen Evolution Reaction ◽  
Influential Factors ◽  
Future Research ◽  
Limiting Factor ◽  
Synthesis Methods ◽  
High Catalytic Activity ◽  
Double Hydroxides

Electrochemical water splitting driven by clean and sustainable energy sources to produce hydrogen is an efficient and environmentally friendly energy conversion technology. Water splitting involves hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in which OER is the limiting factor and has attracted extensive research interest in the past few years. Conventional noble-metal-based OER electrocatalysts like IrO2 and RuO2 suffer from the limitations of high cost and scarce availability. Developing innovative alternative nonnoble metal electrocatalysts with high catalytic activity and long-term durability to boost the OER process remains a significant challenge. Among all of the candidates for OER catalysis, self-supported layered double hydroxides (LDHs) have emerged as one of the most promising types of electrocatalysts due to their unique layered structures and high electrocatalytic activity. In this review, we summarize the recent progress on self-supported LDHs and highlight their electrochemical catalytic performance. Specifically, synthesis methods, structural and compositional parameters, and influential factors for optimizing OER performance are discussed in detail. Finally, the remaining challenges facing the development of self-supported LDHs are discussed and perspectives on their potential for use in industrial hydrogen production through water splitting are provided to suggest future research directions.

Synthesis of Organic-Intercalated Zn/Fe Layered Double Hydroxides from the Electroplating Wastewater

2012 ◽  
Vol 610-613 ◽  
pp. 538-541
Author(s):  
Xiu Xiu Ruan ◽  
Song Huang ◽  
Hua Chen
Keyword(s):  
Charge Density ◽  
Layered Double Hydroxides ◽  
Removal Rate ◽  
Interlamellar Spacing ◽  
Organic Contaminant ◽  
Precipitation Method ◽  
Synthesis Product ◽  
High Concentration ◽  
Electroplating Wastewater ◽  
Double Hydroxides

A series of dodecyl sulfate (DS-) intercalated Zn/Fe layered double hydroxides (DS-Zn/Fe-LDHs) were prepared by co-precipitation method from the electroplating wastewater containing high concentration of zinc (Zn2+). In addition, the influences of their charge density on the interlayer structure of LDHs were investigated by XRD and FT-IR. The removal rate of Zn2+ in the electroplating wastewater was reached 99.9%. The charge density decreased with the increasing of the ratio of Zn/Fe. The results showed that with the increase of the charge density, the interlamellar spacing of organic-LDH increased. The synthesis product was applied in the sorption of organic contaminant ( nitrobenzene ) and the sorption mechanism was partition. The synthetic DS-Zn/Fe LDHs were good sorbents for organic contaminant.

scholarly journals Sepiolite-Hydrogels: Synthesis by Ultrasound Irradiation and Their Use for the Preparation of Functional Clay-Based Nanoarchitectured Materials

2021 ◽  
Vol 9 ◽  
Author(s):  
Eduardo Ruiz-Hitzky ◽  
Cristina Ruiz-García ◽  
Francisco M. Fernandes ◽  
Giulia Lo Dico ◽  
Lorenzo Lisuzzo ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
High Speed ◽  
Structural Characteristics ◽  
Functional Materials ◽  
Ultrasound Irradiation ◽  
High Viscosity ◽  
Low Density ◽  
Colloidal Systems ◽  
Micro Particles ◽  
Double Hydroxides

Sepiolite and palygorskite fibrous clay minerals are 1D silicates featuring unique textural and structural characteristics useful in diverse applications, and in particular as rheological additives. Here we report on the ability of grinded sepiolite to generate highly viscous and stable hydrogels by sonomechanical irradiation (ultrasounds). Adequate drying of such hydrogels leads to low-density xerogels that show extensive fiber disaggregation compared to the starting sepiolite—whose fibers are agglomerated as bundles. Upon re-dispersion in water under high-speed shear, these xerogels show comparable rheological properties to commercially available defibrillated sepiolite products, resulting in high viscosity hydrogels that minimize syneresis. These colloidal systems are thus very interesting as they can be used to stabilize many diverse compounds as well as nano-/micro-particles, leading to the production of a large variety of composites and nano/micro-architectured solids. In this context, we report here various examples showing how colloidal routes based on sepiolite hydrogels can be used to obtain new heterostructured functional materials, based on their assembly to solids of diverse topology and composition such as 2D and 1D kaolinite and halloysite aluminosilicates, as well as to the 2D synthetic Mg,Al-layered double hydroxides (LDH).

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