Layered double hydroxides (LDHs)-based photocatalysts for dye degradation: a review

Discharge of dye-contaminated effluents in aquatic environments has major detrimental effects on aquatic ecosystem as well as on human health. Various technologies have been employed to treat dye-contaminated water. Recently, layered double hydroxides (LDHs) and their derivatives have attracted a lot of attention for managing dye-contaminated water due to their variable shapes, steadiness, high surface area, uniform positive charge dissemination on the surface, interplanar spacing, and simplicity of synthesis and adaptability to prepare different type of composites. This review paper presents an overview on dye-contaminated water treatment using LDHs and their derivatives. This review summarizes the photocatalytic applications of LDHs & their derivatives for the removal of dye contaminants from wastewater. Photocatalytic efficiency and kinetics of photodegradation using different LDHs are described in brief. LDH photocatalysts-mediated degradation mechanisms are also elucidated. Effect of photocatalyst dose, pH, initial concentration of dyes on photodegradation efficiency are also explained. Finally, the stability, regeneration, and reusability of various LDH- and their derivative-based photocatalysts are discussed.Graphical abstract