Advances in the Morphological Design and Dimensional Approaches of Layered Double Hydroxides for Photocatalytic Applications: A Critical Review

Layered double hydroxides (LDHs) have received broad recognition in the photocatalytic technology field, because of their compositional flexibility, layered structure, and tunable optoelectronic properties, which are critical to optimizing the spectral-response activity. Engineering the morphological structure into various dimensional sizes could influence the photocatalytic attributes of the LDH-based nanohybrids. Therefore, a comprehensive understanding of LDH synthesis and parameter regulation to achieve various dimensional structures is essential for designing highly efficient LDH materials. Therefore, this Review describes the design control mechanisms that influence the morphological dimensions of LDHs with views of the reaction parameters, fundamentals, challenges, and photophysical properties. It highlights the development of various LDH structures such as quantum dots, nanosheets, monolayers, hierarchical forms, core-shells, and layer-by-layer nanostructures. Furthermore, this review discusses recent advances in the engineering of LDH nanohybrids for photocatalytic energy conversion and water remediation. Finally, future prospects are provided to elevate the potential of LDHs as promising materials for photocatalytic applications.