Layered Double Hydroxide-Based Photocatalysts for the Removal of Emerging Contaminants: Progress in Past Ten Years

Currently, public health is seriously threatened by the massive concentrations of emerging contaminants. Treating emerging contaminants in water using effective methods has become a major challenge worldwide. Photocatalytic technology, as an eco-friendly technology, has been recognized as an effective means of removing contaminants from water. Among the various photocatalysts, layered double hydroxides (LDHs), known as hydrotalcite-like materials, have been explored extensively in photocatalytic reactions due to their switchable properties and the large surface areas of their unique two-dimensional structures. In this article, recent advances in the photocatalytic degradation of emerging contaminants by LDH-based photocatalysts are reviewed. Firstly, the fundamental principles of the photocatalytic degradation of emerging contaminants using LDH-based materials are briefly introduced. Various LDHs applied in the photocatalytic degradation of emerging contaminants are broadly summarized into four types: pure-phase LDHs, interlayer-modified LDHs, LDH-based composites, and layered double oxides (LDOs). Moreover, the synthesis process and catalytic mechanism of LDH-based photocatalysts are also reviewed. An outlook on the problems and future development of LDH-based photocatalysts in water remediation is provided at the end.