A comprehensive review of two-dimensional high-entropy layered hydroxides: Synthesis, characterization, and applications

High-entropy layered double hydroxides (HE-LDHs) are complex materials with customizable properties achieved by selecting specific elements and stoichiometric adjustments. These materials typically contain five or more elements enabling tailored properties such as enhanced stability, catalytic activity, and electronic conductivity. Although high-entropy oxides and alloys have been extensively researched, HE-LDHs represent a new frontier in multifunctional materials. Recent advancements in their applications, particularly in energy storage, conversion systems and environmental remediation, are highlighted in this review. Effective synthesis strategies, including co-precipitation, hydrothermal, solvothermal, and electrodeposition methods, are crucial for tailoring the compositions and properties of HE-LDHs. Fundamental insights into their unique advantages, such as high configurational entropy, enhancing structural stability and resistance to degradation, are also explored. The paper addresses synthesis challenges and practical applications, providing guidelines for researchers aiming to advance the next generation of materials in this field.