One-Step Synthesis of Layered Double Hydroxides by a Solvent-Free Method

Layered double hydroxides (LDHs), a class of layered materials with versatile applications, are commonly prepared in an alkaline solution, by using coprecipitation, hydrothermal, sol-gel and reconstruction method, where a large amount of water is required. A few mechanochemical synthesis methods have been attempted to reduce the use of water and thus waste solutions, while these methods involve complicated steps. Herein we report a simple one step and solvent-free method for synthesizing various LDHs with different cations. Compared to conventional approaches, this green preparation method saves water and raw materials, reduces the pollutants, simplifies synthetic procedures, and enhances the synthesis efficiency. The obtained LDHs feature an ultrathin structure and contain rich exchangeable sites with improved sorption properties. Therefore, the results provide a green and robust method for the industrial-scale synthesis of LDHs in the future.