Trends in Layered Double Hydroxides‐Based Advanced Nanocomposites: Recent Progress and Latest Advancements

Abstract

Recently, layered double hydroxides (LDHs) have gathered vast interest due to overall positive charge, unique crystallinity, and biocompatibility for diverse applications. Despite the advantageous attributes, these hydrotalcites often result in several limitations concerning the application requirements, such as aggregation, as well as poor chemical and thermal stabilities, hindering their scale‐up progress and practical utilization. In addressing these issues, the recent advancements in the fabrication of intelligent LDHs nanocomposites based on organically (polymer/polyelectrolyte)‐modified and inorganic (metal)‐composited architectures are systematically presented. Initially, a brief note on the shortcomings in various fields and the chemistry of these pristine LDHs is given. Then, various synthetic strategies used to fabricate these emerging LDH nanocomposites are comprehensively emphasized, focusing on the advancements in their structure and applicability. In addition, the effects of various attractive physicochemical attributes of LDHs and their nanocomposite forms are discussed, including their applicability in adsorption, biomedicine, catalysis, energy, and environment‐related applications. In summary, this article is concluded with an outlook concerning the positioning of LDH‐based nanocomposites compared to other innovative materials, as well as the current challenges and future requirements for scale‐up.

Hollow Nickel Nanochains Coated with Nickel-Iron Hydroxide for Oxygen Evolution

“…Consequently, extensive research efforts have been focused on developing alternative water electrolysis catalysts based on transition metal compounds, such as perovskite oxides, , carbides, nitrides, phosphides, and sulfides . Additionally, layered double hydroxides (LDHs), which are two-dimensional materials with layered structures, have been recognized as excellent catalysts owing to their relatively large surface area and anion exchange ability. , The introduction of highly oxidized transition metal ions into LDHs has a synergistic effect on the catalytic activity of OER. − However, LDHs suffer from low electrical conductivity and weak structural stability, owing to the presence of anions and water molecules between their layers. − To overcome these drawbacks, transition metals have been combined with carbon nanostructures to produce systems such as NiFe-graphene, , NiCo-graphene, and NiFe-carbon nanotubes . The electrical conductivity limit has been improved through the hierarchical growth of an LDH structure on a precious metal framework with excellent conductivity .…”

“…However, it is challenging to incorporate metals into the carbon nanostructures while controlling the morphology and structure during the growth process. Moreover, using expensive metals as templates is not a viable strategy for developing alternative catalysts. , …”

“…Moreover, using expensive metals as templates is not a viable strategy for developing alternative catalysts. 24,25 Despite a few limitations, the direct growth of LDHs on transition-metal-based templates to produce electrode materials has been continuously explored. 29−36 Notably, this approach features a simple synthesis methodology, in which galvanic corrosion triggers the spontaneous growth of an LDH on a template.…”

Scalable Synthesis of Amine-Grafted Ultrafine Layered Double Hydroxide Nanosheets with Improved Carbon Dioxide Capture Capacity from Air

“…Recently, modified layered double hydroxides (LDHs)-derived materials have been reported positive for CO 2 capture from air. − LDHs are a family of two-dimensional layered materials with the general formula of false[ normalM 1 − x italicz + normalM x italicy + false( OH false) 2 false] x + false( normalA italicn − false) italicx / italicn · m normalH 2 normalO (M z + and M y + are typically bivalent and trivalent metal species, respectively; A n – represents interlayer anions). Water molecules can also occupy the interlayer and form strong hydrogen bonds with the cationic layer and hydrophilic anions. , The tunability and relatively low cost of LDHs are inherent advantages for their wide applications such as adsorbents. Furthermore, their abundant slit-like mesoporous structure allows LDHs to load large amounts of amine molecules.…”

“…Water molecules can also occupy the interlayer and form strong hydrogen bonds with the cationic layer and hydrophilic anions. 10,11 The tunability and relatively low cost of LDHs are inherent advantages for their wide applications 12 stabilities. 8 Linear triamine-grafted Mg 0.55 Al−CO 3 reached a 70% CO 2 adsorption capacity within 30 min and did not degrade over 50 adsorption−desorption cycles under simulated DAC conditions.…”